<!DOCTYPE html>
<html lang="en"><head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
   <title>Web Distributed Authoring and Versioning (WebDAV) Access&nbsp;Control&nbsp;Protocol</title><script type="application/javascript">
function getMeta(rfcno, container) {

  var xhr = new XMLHttpRequest();
  xhr.open("GET", "https://tools.ietf.org/draft/rfc" + rfcno + "/state.xml", true);
  xhr.onload = function (e) {
    if (xhr.readyState === 4) {
      if (xhr.status === 200) {
        var doc = xhr.responseXML;
        var info = getChildByName(doc.documentElement, "info");
  
        var cont = document.getElementById(container);
        // empty the container
        while (cont.firstChild) {
          cont.removeChild(myNode.firstChild);
        }      
  
        var c = getChildByName(info, "stdstatus");
        if (c !== null) {
          var bld = newElementWithText("b", c.textContent);
          cont.appendChild(bld);
        }
  
        c = getChildByName(info, "updatedby");
        if (c !== null) {
          cont.appendChild(newElement("br"));
          cont.appendChild(newText("Updated by: "));
          appendRfcLinks(cont, c.textContent);
        }
  
        c = getChildByName(info, "obsoletedby");
        if (c !== null) {
          cont.appendChild(newElement("br"));
          cont.appendChild(newText("Obsoleted by: "));
          appendRfcLinks(cont, c.textContent);
        }
        
        c = getChildByName(info, "errata");
        if (c !== null) {
          cont.appendChild(newElement("br"));
          var link = newElementWithText("a", "errata");
          link.setAttribute("href", "http://www.rfc-editor.org/errata_search.php?rfc=" + rfcno);
          var errata = newElementWithText("i", "This document has ");
          errata.appendChild(link);
          errata.appendChild(newText("."));
          cont.appendChild(errata);
        }

        cont.style.display = "block";
      } else {
        console.error(xhr.statusText);
      }
    }
  };
  xhr.onerror = function (e) {
    console.error(xhr.status + " " + xhr.statusText);
  };
  xhr.send(null);
}

// DOM helpers
function newElement(name) {
  return document.createElement(name);
}
function newElementWithText(name, txt) {
  var e = document.createElement(name);
  e.appendChild(newText(txt));
  return e;
}
function newText(text) {
  return document.createTextNode(text);
}

function getChildByName(parent, name) {
  if (parent === null) {
    return null;
  }
  else {
    for (var c = parent.firstChild; c !== null; c = c.nextSibling) {
      if (name == c.nodeName) {
        return c;
      }
    }
    return null;
  }
}

function appendRfcLinks(parent, text) {
  var updates = text.split(",");
  for (var i = 0; i < updates.length; i++) {
    var rfc = updates[i].trim();
    if (rfc.substring(0, 3) == "rfc") {
      var link = newElement("a");
      link.setAttribute("href", "http://tools.ietf.org/html/" + rfc);
      link.appendChild(newText(rfc.substring(3)));
      parent.appendChild(link);
    } else {
      parent.appendChild(newText(rfc));
    }
    if (i != updates.length - 1) {
      parent.appendChild(newText(", "));
    }
  }
}
</script><script type="application/javascript">
function anchorRewrite() {
  map = { };
  if (window.location.hash.length >= 1) {
    var fragid = window.location.hash.substr(1);
    if (fragid) {
      if (! document.getElementById(fragid)) {
        var prefix = "rfc.";
        var mapped = map[fragid];
        if (mapped) {
          window.location.hash = mapped;
        } else if (fragid.indexOf("section-") == 0) {
          window.location.hash = prefix + "section." + fragid.substring(8);
        } else if (fragid.indexOf("appendix-") == 0) {
          window.location.hash = prefix + "section." + fragid.substring(9);
        } else if (fragid.indexOf("s-") == 0) {
          window.location.hash = prefix + "section." + fragid.substring(2);
        } else if (fragid.indexOf("p-") == 0) {
          var r = fragid.substring(2);
          var p = r.indexOf("-");
          if (p >= 0) {
            window.location.hash = prefix + "section." + r.substring(0, p) + ".p." + r.substring(p + 1);
          }
        }
      }
    }  
  }
}
window.addEventListener('hashchange', anchorRewrite);
window.addEventListener('DOMContentLoaded', anchorRewrite);
</script><style type="text/css" title="Xml2Rfc (sans serif)">
a {
  text-decoration: none;
}
a.smpl {
  color: black;
}
a:hover {
  text-decoration: underline;
}
a:active {
  text-decoration: underline;
}
address {
  margin-top: 1em;
  margin-left: 2em;
  font-style: normal;
}
body {
  color: black;
  font-family: cambria, georgia, serif;
  font-size: 12pt;
  margin: 2em auto;
  max-width: 1000px;
}
samp, span.tt, code, pre {
  font-family: consolas, monaco, monospace;
}
cite {
  font-style: normal;
}
dl {
  margin-left: 2em;
}
dl > dt {
  float: left;
  margin-right: 1em;
}
dl.nohang > dt {
  float: none;
}
dl > dd {
  margin-bottom: .5em;
}
dl.compact > dd {
  margin-bottom: .0em;
}
dl > dd > dl {
  margin-top: 0.5em;
}
ul.empty {
  list-style-type: none;
}
ul.empty li {
  margin-top: .5em;
}
dl p {
  margin-left: 0em;
}
dl.reference > dt {
  font-weight: bold;
}
dl.reference > dd {
  margin-left: 6em;
}
h1 {
  color: green;
  font-size: 150%;
  line-height: 18pt;
  font-weight: bold;
  text-align: center;
  margin-top: 36pt;
  margin-bottom: 0pt;
}
h2 {
  font-size: 130%;
  line-height: 21pt;
  page-break-after: avoid;
}
h2.np {
  page-break-before: always;
}
h3 {
  font-size: 120%;
  line-height: 15pt;
  page-break-after: avoid;
}
h4 {
  font-size: 110%;
  page-break-after: avoid;
}
h5, h6 {
  page-break-after: avoid;
}
h1 a, h2 a, h3 a, h4 a, h5 a, h6 a {
  color: black;
}
img {
  margin-left: 3em;
}
li {
  margin-left: 2em;
}
ol {
  margin-left: 2em;
}
ol.la {
  list-style-type: lower-alpha;
}
ol.ua {
  list-style-type: upper-alpha;
}
ol p {
  margin-left: 0em;
}
p {
  margin-left: 2em;
}
pre {
  font-size: 11pt;
  margin-left: 3em;
  background-color: lightyellow;
  padding: .25em;
  page-break-inside: avoid;
}
pre.text2 {
  border-style: dotted;
  border-width: 1px;
  background-color: #f0f0f0;
}
pre.inline {
  background-color: white;
  padding: 0em;
  page-break-inside: auto;
}
pre.text {
  border-style: dotted;
  border-width: 1px;
  background-color: #f8f8f8;
}
pre.drawing {
  border-style: solid;
  border-width: 1px;
  background-color: #f8f8f8;
  padding: 2em;
}
table {
  margin-left: 2em;
}
div.tt {
  margin-left: 2em;
} 
table.tt {
  border-collapse: collapse;
  border-color: gray;
  border-spacing: 0; 
  vertical-align: top;
 }
table.tt th {
  border-color: gray;
  padding: 3px;
}
table.tt td {
  border-color: gray;
  padding: 3px;
}
table.all {
  border-style: solid;
  border-width: 2px;
}
table.full {
  border-style: solid;
  border-width: 2px;
}
table.tt td {
  vertical-align: top;
}
table.all td {
  border-style: solid;
  border-width: 1px;
}
table.full td {
  border-style: none solid;
  border-width: 1px;
}
table.tt th {
  vertical-align: top;
}
table.all th {
  border-style: solid;
  border-width: 1px;
}
table.full th {
  border-style: solid;
  border-width: 1px 1px 2px 1px;
}
table.headers th {
  border-style: none none solid none;
  border-width: 2px;
}
table.tleft {
  margin-right: auto;
}
table.tright {
  margin-left: auto;
}
table.tcenter {
  margin-left: auto;
  margin-right: auto;
}
caption {
  caption-side: bottom;
  font-weight: bold;
  font-size: 10pt;
  margin-top: .5em;
}

table.header {
  border-spacing: 1px;
  width: 95%;
  font-size: 11pt;
  color: white;
}
td.top {
  vertical-align: top;
}
td.topnowrap {
  vertical-align: top;
  white-space: nowrap;
}
table.header td {
  background-color: gray;
  width: 50%;
}
ul.toc, ul.toc ul {
  list-style: none;
  margin-left: 1.5em;
  padding-left: 0em;
}
ul.toc li {
  line-height: 150%;
  font-weight: bold;
  margin-left: 0em;
}
ul.toc li li {
  line-height: normal;
  font-weight: normal;
  font-size: 11pt;
  margin-left: 0em;
}
li.excluded {
  font-size: 0pt;
}
ul p {
  margin-left: 0em;
}
.filename, h1, h2, h3, h4 {
  font-family: candara, calibri, segoe, optima, arial, sans-serif;
}
ul.ind, ul.ind ul {
  list-style: none;
  margin-left: 1.5em;
  padding-left: 0em;
  page-break-before: avoid;
}
ul.ind li {
  font-weight: bold;
  line-height: 200%;
  margin-left: 0em;
}
ul.ind li li {
  font-weight: normal;
  line-height: 150%;
  margin-left: 0em;
}
.avoidbreakinside {
  page-break-inside: avoid;
}
.avoidbreakafter {
  page-break-after: avoid;
}
.bcp14 {
  font-style: normal;
  text-transform: lowercase;
  font-variant: small-caps;
}
.comment {
  background-color: yellow;
}
.center {
  text-align: center;
}
.error {
  color: red;
  font-style: italic;
  font-weight: bold;
}
.figure {
  font-weight: bold;
  text-align: center;
  font-size: 10pt;
}
.filename {
  color: #333333;
  font-size: 112%;
  font-weight: bold;
  line-height: 21pt;
  text-align: center;
  margin-top: 0pt;
}
.fn {
  font-weight: bold;
}
.left {
  text-align: left;
}
.right {
  text-align: right;
}
.warning {
  font-size: 130%;
  background-color: yellow;
}
.self {
    color: #999999;
    margin-left: .3em;
    text-decoration: none;
    visibility: hidden;
    -webkit-user-select: none; 
    -moz-user-select: none;
    -ms-user-select: none;
}
.self:hover {
    text-decoration: none;
}
p:hover .self {
    visibility: visible;
}
.docstatus {
  border: 1px solid black;
  display: none;
  float: right;
  margin: 2em;
  padding: 1em;
}

@media screen {
  pre.text, pre.text2 {
    width: 69em;
  }
}

@media print {
  .noprint {
    display: none;
  }

  a {
    color: black;
    text-decoration: none;
  }

  table.header {
    width: 90%;
  }

  td.header {
    width: 50%;
    color: black;
    background-color: white;
    vertical-align: top;
    font-size: 110%;
  }

  ul.toc a:last-child::after {
    content: leader('.') target-counter(attr(href), page);
  }

  ul.ind li li a {
    content: target-counter(attr(href), page);
  }

  pre {
    font-size: 10pt;
  }

  .print2col {
    column-count: 2;
    -moz-column-count: 2;
    column-fill: auto;
  }
}
@page {
  @top-left {
       content: "RFC 3744";
  }
  @top-right {
       content: "May 2004";
  }
  @top-center {
       content: "WebDAV Access Control Protocol";
  }
  @bottom-left {
       content: "Clemm, et al.";
  }
  @bottom-center {
       content: "Standards Track";
  }
  @bottom-right {
       content: "[Page " counter(page) "]";
  }
}
@page:first {
    @top-left {
      content: normal;
    }
    @top-right {
      content: normal;
    }
    @top-center {
      content: normal;
    }
}
</style><link rel="Contents" href="#rfc.toc"><link rel="Author" href="#rfc.authors"><link rel="Copyright" href="#rfc.copyright"><link rel="Index" href="#rfc.index"><link rel="Chapter" title="1 Introduction" href="#rfc.section.1"><link rel="Chapter" title="2 Principals" href="#rfc.section.2"><link rel="Chapter" title="3 Privileges" href="#rfc.section.3"><link rel="Chapter" title="4 Principal Properties" href="#rfc.section.4"><link rel="Chapter" title="5 Access Control Properties" href="#rfc.section.5"><link rel="Chapter" title="6 ACL Evaluation" href="#rfc.section.6"><link rel="Chapter" title="7 Access Control and existing methods" href="#rfc.section.7"><link rel="Chapter" title="8 Access Control Methods" href="#rfc.section.8"><link rel="Chapter" title="9 Access Control Reports" href="#rfc.section.9"><link rel="Chapter" title="10 XML Processing" href="#rfc.section.10"><link rel="Chapter" title="11 Internationalization Considerations" href="#rfc.section.11"><link rel="Chapter" title="12 Security Considerations" href="#rfc.section.12"><link rel="Chapter" title="13 Authentication" href="#rfc.section.13"><link rel="Chapter" title="14 IANA Considerations" href="#rfc.section.14"><link rel="Chapter" title="15 Acknowledgements" href="#rfc.section.15"><link rel="Chapter" href="#rfc.section.16" title="16 References"><link rel="Appendix" title="A WebDAV XML Document Type Definition Addendum" href="#rfc.section.A"><link rel="Appendix" title="B WebDAV Method Privilege Table (Normative)" href="#rfc.section.B"><link rel="Alternate" title="Authoritative ASCII Version" href="http://www.ietf.org/rfc/rfc3744.txt"><link rel="Help" title="RFC-Editor's Status Page" href="http://www.rfc-editor.org/info/rfc3744"><link rel="Help" title="Additional Information on tools.ietf.org" href="http://tools.ietf.org/html/rfc3744"><meta name="generator" content="http://greenbytes.de/tech/webdav/rfc2629.xslt, Revision 1.840, 2016/11/16 05:32:10, XSLT vendor: SAXON 6.5.5 from Michael Kay http://saxon.sf.net/"><link rel="schema.dcterms" href="http://purl.org/dc/terms/"><meta name="dcterms.creator" content="Clemm, G."><meta name="dcterms.creator" content="Reschke, J. F."><meta name="dcterms.creator" content="Sedlar, E."><meta name="dcterms.creator" content="Whitehead, J."><meta name="dcterms.identifier" content="urn:ietf:rfc:3744"><meta name="dcterms.issued" content="2004-05"><meta name="dcterms.abstract" content="This document specifies a set of methods, headers, message bodies, properties, and reports that define Access Control extensions to the WebDAV Distributed Authoring Protocol. This protocol permits a client to read and modify access control lists that instruct a server whether to allow or deny operations upon a resource (such as HyperText Transfer Protocol (HTTP) method invocations) by a given principal. A lightweight representation of principals as Web resources supports integration of a wide range of user management repositories. Search operations allow discovery and manipulation of principals using human names."><meta name="dcterms.isPartOf" content="urn:issn:2070-1721"><meta name="description" content="This document specifies a set of methods, headers, message bodies, properties, and reports that define Access Control extensions to the WebDAV Distributed Authoring Protocol. This protocol permits a client to read and modify access control lists that instruct a server whether to allow or deny operations upon a resource (such as HyperText Transfer Protocol (HTTP) method invocations) by a given principal. A lightweight representation of principals as Web resources supports integration of a wide range of user management repositories. Search operations allow discovery and manipulation of principals using human names."></head><body onload="getMeta(3744,&#34;rfc.meta&#34;);"><header><table class="header" id="rfc.headerblock"><tbody><tr><td class="left">Network Working Group</td><td class="right">G. Clemm</td></tr><tr><td class="left">Request for Comments: 3744</td><td class="right">IBM</td></tr><tr><td class="left">Category: Standards Track</td><td class="right">J. Reschke</td></tr><tr><td class="left"></td><td class="right">greenbytes</td></tr><tr><td class="left"></td><td class="right">E. Sedlar</td></tr><tr><td class="left"></td><td class="right">Oracle Corporation</td></tr><tr><td class="left"></td><td class="right">J. Whitehead</td></tr><tr><td class="left"></td><td class="right">U.C. Santa Cruz</td></tr><tr><td class="left"></td><td class="right">May 2004</td></tr></tbody></table><div id="rfc.title"><h1>Web Distributed Authoring and Versioning (WebDAV) Access&nbsp;Control&nbsp;Protocol</h1></div></header><div id="rfc.meta" class="docstatus"></div><section id="rfc.status"><h2><a href="#rfc.status">Status of this Memo</a></h2><p>This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the &#8220;Internet Official Protocol Standards&#8221; (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.</p></section><section id="rfc.copyrightnotice"><h2><a href="#rfc.copyrightnotice">Copyright Notice</a></h2><p>Copyright &copy; The Internet Society (2004). All Rights Reserved.</p></section><section id="rfc.abstract"><h2><a href="#rfc.abstract">Abstract</a></h2><p>This document specifies a set of methods, headers, message bodies, properties, and reports that define Access Control extensions to the WebDAV Distributed Authoring Protocol. This protocol permits a client to read and modify access control lists that instruct a server whether to allow or deny operations upon a resource (such as HyperText Transfer Protocol (HTTP) method invocations) by a given principal. A lightweight representation of principals as Web resources supports integration of a wide range of user management repositories. Search operations allow discovery and manipulation of principals using human names.</p></section><hr class="noprint"><nav id="rfc.toc"><h2 class="np"><a href="#rfc.toc">Table of Contents</a></h2><ul class="toc"><li><a href="#rfc.section.1">1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.1">Introduction</a><ul><li><a href="#rfc.section.1.1">1.1.</a>&nbsp;&nbsp;&nbsp;<a href="#terms">Terms</a></li><li><a href="#rfc.section.1.2">1.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.1.2">Notational Conventions</a></li></ul></li><li><a href="#rfc.section.2">2.</a>&nbsp;&nbsp;&nbsp;<a href="#principals">Principals</a></li><li><a href="#rfc.section.3">3.</a>&nbsp;&nbsp;&nbsp;<a href="#privileges">Privileges</a><ul><li><a href="#rfc.section.3.1">3.1.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_read">DAV:read Privilege</a></li><li><a href="#rfc.section.3.2">3.2.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_write">DAV:write Privilege</a></li><li><a href="#rfc.section.3.3">3.3.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_write-properties">DAV:write-properties Privilege</a></li><li><a href="#rfc.section.3.4">3.4.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_write-content">DAV:write-content Privilege</a></li><li><a href="#rfc.section.3.5">3.5.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_unlock">DAV:unlock Privilege</a></li><li><a href="#rfc.section.3.6">3.6.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_read-acl">DAV:read-acl Privilege</a></li><li><a href="#rfc.section.3.7">3.7.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_read-current-user-privilege-set">DAV:read-current-user-privilege-set Privilege</a></li><li><a href="#rfc.section.3.8">3.8.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_write-acl">DAV:write-acl Privilege</a></li><li><a href="#rfc.section.3.9">3.9.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_bind">DAV:bind Privilege</a></li><li><a href="#rfc.section.3.10">3.10.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_unbind">DAV:unbind Privilege</a></li><li><a href="#rfc.section.3.11">3.11.</a>&nbsp;&nbsp;&nbsp;<a href="#PRIVILEGE_all">DAV:all Privilege</a></li><li><a href="#rfc.section.3.12">3.12.</a>&nbsp;&nbsp;&nbsp;<a href="#aggregation.of.predefined.privileges">Aggregation of Predefined Privileges</a></li></ul></li><li><a href="#rfc.section.4">4.</a>&nbsp;&nbsp;&nbsp;<a href="#principal.properties">Principal Properties</a><ul><li><a href="#rfc.section.4.1">4.1.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_alternate-URI-set">DAV:alternate-URI-set</a></li><li><a href="#rfc.section.4.2">4.2.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_principal-URL">DAV:principal-URL</a></li><li><a href="#rfc.section.4.3">4.3.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.4.3">DAV:group-member-set</a></li><li><a href="#rfc.section.4.4">4.4.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.4.4">DAV:group-membership</a></li></ul></li><li><a href="#rfc.section.5">5.</a>&nbsp;&nbsp;&nbsp;<a href="#access.control.properties">Access Control Properties</a><ul><li><a href="#rfc.section.5.1">5.1.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_owner">DAV:owner</a><ul><li><a href="#rfc.section.5.1.1">5.1.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.1.1">Example: Retrieving DAV:owner</a></li><li><a href="#rfc.section.5.1.2">5.1.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.1.2">Example: An Attempt to Set DAV:owner</a></li></ul></li><li><a href="#rfc.section.5.2">5.2.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_group">DAV:group</a></li><li><a href="#rfc.section.5.3">5.3.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_supported-privilege-set">DAV:supported-privilege-set</a><ul><li><a href="#rfc.section.5.3.1">5.3.1.</a>&nbsp;&nbsp;&nbsp;<a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource">Example: Retrieving a List of Privileges Supported on a Resource</a></li></ul></li><li><a href="#rfc.section.5.4">5.4.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_current-user-privilege-set">DAV:current-user-privilege-set</a><ul><li><a href="#rfc.section.5.4.1">5.4.1.</a>&nbsp;&nbsp;&nbsp;<a href="#example.retrieving.the.users.current.set.of.assigned.privileges">Example: Retrieving the User's Current Set of Assigned Privileges</a></li></ul></li><li><a href="#rfc.section.5.5">5.5.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_acl">DAV:acl</a><ul><li><a href="#rfc.section.5.5.1">5.5.1.</a>&nbsp;&nbsp;&nbsp;<a href="#ace.principal">ACE Principal</a></li><li><a href="#rfc.section.5.5.2">5.5.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.5.2">ACE Grant and Deny</a></li><li><a href="#rfc.section.5.5.3">5.5.3.</a>&nbsp;&nbsp;&nbsp;<a href="#ace.protection">ACE Protection</a></li><li><a href="#rfc.section.5.5.4">5.5.4.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.5.4">ACE Inheritance</a></li><li><a href="#rfc.section.5.5.5">5.5.5.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.5.5">Example: Retrieving a Resource's Access Control List</a></li></ul></li><li><a href="#rfc.section.5.6">5.6.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_acl-restrictions">DAV:acl-restrictions</a><ul><li><a href="#rfc.section.5.6.1">5.6.1.</a>&nbsp;&nbsp;&nbsp;<a href="#RESTRICTIONS_grant-only">DAV:grant-only</a></li><li><a href="#rfc.section.5.6.2">5.6.2.</a>&nbsp;&nbsp;&nbsp;<a href="#CONSTRAINT_no-invert">DAV:no-invert ACE Constraint</a></li><li><a href="#rfc.section.5.6.3">5.6.3.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.6.3">DAV:deny-before-grant</a></li><li><a href="#rfc.section.5.6.4">5.6.4.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.6.4">Required Principals</a></li><li><a href="#rfc.section.5.6.5">5.6.5.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.6.5">Example: Retrieving DAV:acl-restrictions</a></li></ul></li><li><a href="#rfc.section.5.7">5.7.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_inherited-acl-set">DAV:inherited-acl-set</a></li><li><a href="#rfc.section.5.8">5.8.</a>&nbsp;&nbsp;&nbsp;<a href="#PROPERTY_principal-collection-set">DAV:principal-collection-set</a><ul><li><a href="#rfc.section.5.8.1">5.8.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.8.1">Example: Retrieving DAV:principal-collection-set</a></li></ul></li><li><a href="#rfc.section.5.9">5.9.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.5.9">Example: PROPFIND to retrieve access control properties</a></li></ul></li><li><a href="#rfc.section.6">6.</a>&nbsp;&nbsp;&nbsp;<a href="#acl.evaluation">ACL Evaluation</a></li><li><a href="#rfc.section.7">7.</a>&nbsp;&nbsp;&nbsp;<a href="#access.control.and.existing.methods">Access Control and existing methods</a><ul><li><a href="#rfc.section.7.1">7.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.1">Any HTTP method</a><ul><li><a href="#rfc.section.7.1.1">7.1.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.1.1">Error Handling</a></li></ul></li><li><a href="#rfc.section.7.2">7.2.</a>&nbsp;&nbsp;&nbsp;<a href="#METHOD_options">OPTIONS</a><ul><li><a href="#rfc.section.7.2.1">7.2.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.2.1">Example - OPTIONS</a></li></ul></li><li><a href="#rfc.section.7.3">7.3.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.3">MOVE</a></li><li><a href="#rfc.section.7.4">7.4.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.4">COPY</a></li><li><a href="#rfc.section.7.5">7.5.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.7.5">LOCK</a></li></ul></li><li><a href="#rfc.section.8">8.</a>&nbsp;&nbsp;&nbsp;<a href="#access.control.methods">Access Control Methods</a><ul><li><a href="#rfc.section.8.1">8.1.</a>&nbsp;&nbsp;&nbsp;<a href="#METHOD_ACL">ACL</a><ul><li><a href="#rfc.section.8.1.1">8.1.1.</a>&nbsp;&nbsp;&nbsp;<a href="#acl.preconditions">ACL Preconditions</a></li><li><a href="#rfc.section.8.1.2">8.1.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.8.1.2">Example: the ACL method</a></li><li><a href="#rfc.section.8.1.3">8.1.3.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.8.1.3">Example: ACL method failure due to protected ACE conflict</a></li><li><a href="#rfc.section.8.1.4">8.1.4.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.8.1.4">Example: ACL method failure due to an inherited ACE conflict</a></li><li><a href="#rfc.section.8.1.5">8.1.5.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.8.1.5">Example: ACL method failure due to an attempt to set grant and deny in a single ACE</a></li></ul></li></ul></li><li><a href="#rfc.section.9">9.</a>&nbsp;&nbsp;&nbsp;<a href="#access.control.reports">Access Control Reports</a><ul><li><a href="#rfc.section.9.1">9.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.1">REPORT Method</a></li><li><a href="#rfc.section.9.2">9.2.</a>&nbsp;&nbsp;&nbsp;<a href="#REPORT_acl-principal-prop-set">DAV:acl-principal-prop-set Report</a><ul><li><a href="#rfc.section.9.2.1">9.2.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.2.1">Example: DAV:acl-principal-prop-set Report</a></li></ul></li><li><a href="#rfc.section.9.3">9.3.</a>&nbsp;&nbsp;&nbsp;<a href="#REPORT_principal-match">DAV:principal-match REPORT</a><ul><li><a href="#rfc.section.9.3.1">9.3.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.3.1">Example: DAV:principal-match REPORT</a></li></ul></li><li><a href="#rfc.section.9.4">9.4.</a>&nbsp;&nbsp;&nbsp;<a href="#REPORT_principal-property-search">DAV:principal-property-search REPORT</a><ul><li><a href="#rfc.section.9.4.1">9.4.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.4.1">Matching</a></li><li><a href="#rfc.section.9.4.2">9.4.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.4.2">Example: successful DAV:principal-property-search REPORT</a></li></ul></li><li><a href="#rfc.section.9.5">9.5.</a>&nbsp;&nbsp;&nbsp;<a href="#REPORT_principal-search-property-set">DAV:principal-search-property-set REPORT</a><ul><li><a href="#rfc.section.9.5.1">9.5.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.9.5.1">Example: DAV:principal-search-property-set REPORT</a></li></ul></li></ul></li><li><a href="#rfc.section.10">10.</a>&nbsp;&nbsp;&nbsp;<a href="#xml.processing">XML Processing</a></li><li><a href="#rfc.section.11">11.</a>&nbsp;&nbsp;&nbsp;<a href="#internationalization.considerations">Internationalization Considerations</a></li><li><a href="#rfc.section.12">12.</a>&nbsp;&nbsp;&nbsp;<a href="#security.considerations">Security Considerations</a><ul><li><a href="#rfc.section.12.1">12.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.12.1">Increased Risk of Compromised Users</a></li><li><a href="#rfc.section.12.2">12.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.12.2">Risks of the DAV:read-acl and DAV:current-user-privilege-set Privileges</a></li><li><a href="#rfc.section.12.3">12.3.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.12.3">No Foreknowledge of Initial ACL</a></li></ul></li><li><a href="#rfc.section.13">13.</a>&nbsp;&nbsp;&nbsp;<a href="#authentication">Authentication</a></li><li><a href="#rfc.section.14">14.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.14">IANA Considerations</a></li><li><a href="#rfc.section.15">15.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.15">Acknowledgements</a></li><li><a href="#rfc.section.16">16.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references">References</a><ul><li><a href="#rfc.section.16.1">16.1.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.1">Normative References</a></li><li><a href="#rfc.section.16.2">16.2.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.references.2">Informative References</a></li></ul></li><li><a href="#rfc.section.A">A.</a>&nbsp;&nbsp;&nbsp;<a href="#webdav.xml.document.type.definition.addendum">WebDAV XML Document Type Definition Addendum</a></li><li><a href="#rfc.section.B">B.</a>&nbsp;&nbsp;&nbsp;<a href="#rfc.section.B">WebDAV Method Privilege Table (Normative)</a></li><li><a href="#rfc.index">Index</a></li><li><a href="#rfc.authors">Authors' Addresses</a></li><li><a href="#rfc.ipr">Intellectual Property and Copyright Statements</a></li></ul></nav><section id="n-introduction"><h2 id="rfc.section.1" class="np"><a href="#rfc.section.1">1.</a>&nbsp;<a href="#n-introduction">Introduction</a></h2><div id="rfc.section.1.p.1"><p>The goal of the WebDAV access control extensions is to provide an interoperable mechanism for handling discretionary access control for content and metadata managed by WebDAV servers. WebDAV access control can be implemented on content repositories with security as simple as that of a UNIX file system, as well as more sophisticated models. The underlying principle of access control is that who you are determines what operations you can perform on a resource. The "who you are" is defined by a "principal" identifier; users, client software, servers, and groups of the previous have principal identifiers. The "operations you can perform" are determined by a single "access control list" (ACL) associated with a resource. An ACL contains a set of "access control entries" (ACEs), where each ACE specifies a principal and a set of privileges that are either granted or denied to that principal. When a principal submits an operation (such as an HTTP or WebDAV method) to a resource for execution, the server evaluates the ACEs in the ACL to determine if the principal has permission for that operation.<a class="self" href="#rfc.section.1.p.1">&para;</a></p></div><div id="rfc.section.1.p.2"><p>Since every ACE contains the identifier of a principal, client software operated by a human must provide a mechanism for selecting this principal. This specification uses http(s) scheme URLs to identify principals, which are represented as WebDAV-capable resources. There is no guarantee that the URLs identifying principals will be meaningful to a human. For example, http://www.example.com/u/256432 and http://www.example.com/people/Greg.Stein are both valid URLs that could be used to identify the same principal. To remedy this, every principal resource has the DAV:displayname property containing a human-readable name for the principal.<a class="self" href="#rfc.section.1.p.2">&para;</a></p></div><div id="rfc.section.1.p.3"><p>Since a principal can be identified by multiple URLs, it raises the problem of determining exactly which principal is being referenced in a given ACE. It is impossible for a client to determine that an ACE granting the read privilege to http://www.example.com/people/Greg.Stein also affects the principal at http://www.example.com/u/256432. That is, a client has no mechanism for determining that two URLs identify the same principal resource. As a result, this specification requires clients to use just one of the many possible URLs for a principal when creating ACEs. A client can discover which URL to use by retrieving the DAV:principal-URL property (<a href="#PROPERTY_principal-URL" title="DAV:principal-URL">Section&nbsp;4.2</a>) from a principal resource. No matter which of the principal's URLs is used with PROPFIND, the property always returns the same URL.<a class="self" href="#rfc.section.1.p.3">&para;</a></p></div><div id="rfc.section.1.p.4"><p>With a system having hundreds to thousands of principals, the problem arises of how to allow a human operator of client software to select just one of these principals. One approach is to use broad collection hierarchies to spread the principals over a large number of collections, yielding few principals per collection. An example of this is a two level hierarchy with the first level containing 36 collections (a-z, 0-9), and the second level being another 36, creating collections /a/a/, /a/b/, ..., /a/z/, such that a principal with last name "Stein" would appear at /s/t/Stein. In effect, this pre-computes a common query, search on last name, and encodes it into a hierarchy. The drawback with this scheme is that it handles only a small set of predefined queries, and drilling down through the collection hierarchy adds unnecessary steps (navigate down/up) when the user already knows the principal's name. While organizing principal URLs into a hierarchy is a valid namespace organization, users should not be forced to navigate this hierarchy to select a principal.<a class="self" href="#rfc.section.1.p.4">&para;</a></p></div><div id="rfc.section.1.p.5"><p>This specification provides the capability to perform substring searches over a small set of properties on the resources representing principals. This permits searches based on last name, first name, user name, job title, etc. Two separate searches are supported, both via the REPORT method, one to search principal resources (DAV:principal-property-search, <a href="#REPORT_principal-property-search" title="DAV:principal-property-search REPORT">Section&nbsp;9.4</a>), the other to determine which properties may be searched at all (DAV:principal-search-property-set, <a href="#REPORT_principal-search-property-set" title="DAV:principal-search-property-set REPORT">Section&nbsp;9.5</a>).<a class="self" href="#rfc.section.1.p.5">&para;</a></p></div><div id="rfc.section.1.p.6"><p>Once a principal has been identified in an ACE, a server evaluating that ACE must know the identity of the principal making a protocol request, and must validate that that principal is who they claim to be, a process known as authentication. This specification intentionally omits discussion of authentication, as the HTTP protocol already has a number of authentication mechanisms <a href="#RFC2617" id="rfc.xref.RFC2617.1"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. Some authentication mechanism (such as HTTP Digest Authentication, which all WebDAV compliant implementations are required to support) must be available to validate the identity of a principal.<a class="self" href="#rfc.section.1.p.6">&para;</a></p></div><div id="rfc.section.1.p.7"><p>The following issues are out of scope for this document: <a class="self" href="#rfc.section.1.p.7">&para;</a></p><ul><li>Access control that applies only to a particular property on a resource (excepting the access control properties DAV:acl and DAV:current-user-privilege-set), rather than the entire resource,</li><li>Role-based security (where a role can be seen as a dynamically defined group of principals),</li><li>Specification of the ways an ACL on a resource is initialized,</li><li>Specification of an ACL that applies globally to all resources, rather than to a particular resource.</li><li>Creation and maintenance of resources representing people or computational agents (principals), and groups of these.</li></ul></div><div id="rfc.section.1.p.8"><p>This specification is organized as follows. <a href="#terms" title="Terms">Section&nbsp;1.1</a> defines key concepts used throughout the specification, and is followed by a more in-depth discussion of principals (<a href="#principals" title="Principals">Section&nbsp;2</a>), and privileges (<a href="#privileges" title="Privileges">Section&nbsp;3</a>). Properties defined on principals are specified in <a href="#principal.properties" title="Principal Properties">Section&nbsp;4</a>, and access control properties for content resources are specified in <a href="#access.control.properties" title="Access Control Properties">Section&nbsp;5</a>. The ways ACLs are to be evaluated is described in <a href="#acl.evaluation" title="ACL Evaluation">Section&nbsp;6</a>. Client discovery of access control capability using OPTIONS is described in <a href="#METHOD_options" title="OPTIONS">Section&nbsp;7.2</a>. Interactions between access control functionality and existing HTTP and WebDAV methods are described in the remainder of <a href="#access.control.and.existing.methods" title="Access Control and existing methods">Section&nbsp;7</a>. The access control setting method, ACL, is specified in <a href="#access.control.methods" title="Access Control Methods">Section&nbsp;8</a>. Four reports that provide limited server-side searching capabilities are described in <a href="#access.control.reports" title="Access Control Reports">Section&nbsp;9</a>. Sections on XML processing (<a href="#xml.processing" title="XML Processing">Section&nbsp;10</a>), Internationalization considerations (<a href="#internationalization.considerations" title="Internationalization Considerations">Section&nbsp;11</a>), security considerations (<a href="#security.considerations" title="Security Considerations">Section&nbsp;12</a>), and authentication (<a href="#authentication" title="Authentication">Section&nbsp;13</a>) round out the specification. An appendix (<a href="#webdav.xml.document.type.definition.addendum" title="WebDAV XML Document Type Definition Addendum">Appendix&nbsp;A</a>) provides an XML Document Type Definition (DTD) for the XML elements defined in the specification.<a class="self" href="#rfc.section.1.p.8">&para;</a></p></div><section id="terms"><h3 id="rfc.section.1.1"><a href="#rfc.section.1.1">1.1.</a>&nbsp;<a href="#terms">Terms</a></h3><div id="rfc.section.1.1.p.1" class="avoidbreakafter"><p>This document uses the terms defined in HTTP <a href="#RFC2616" id="rfc.xref.RFC2616.1"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a> and WebDAV <a href="#RFC2518" id="rfc.xref.RFC2518.1"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>. In addition, the following terms are defined:<a class="self" href="#rfc.section.1.1.p.1">&para;</a></p></div><div id="rfc.section.1.1.p.2"><p><span id="rfc.iref.p.1"></span> <dfn>principal</dfn> <a class="self" href="#rfc.section.1.1.p.2">&para;</a></p><ul class="empty"><li>A "principal" is a distinct human or computational actor that initiates access to network resources. In this protocol, a principal is an HTTP resource that represents such an actor.</li></ul></div><div id="rfc.section.1.1.p.3"><p><span id="rfc.iref.g.1"></span> <dfn>group</dfn> <a class="self" href="#rfc.section.1.1.p.3">&para;</a></p><ul class="empty"><li>A "group" is a principal that represents a set of other principals.</li></ul></div><div id="rfc.section.1.1.p.4"><p><span id="rfc.iref.p.2"></span> <dfn>privilege</dfn> <a class="self" href="#rfc.section.1.1.p.4">&para;</a></p><ul class="empty"><li>A "privilege" controls access to a particular set of HTTP operations on a resource.</li></ul></div><div id="rfc.section.1.1.p.5"><p><span id="rfc.iref.a.1"></span> <dfn>aggregate privilege</dfn> <a class="self" href="#rfc.section.1.1.p.5">&para;</a></p><ul class="empty"><li>An "aggregate privilege" is a privilege that contains a set of other privileges.</li></ul></div><div id="rfc.section.1.1.p.6"><p><span id="rfc.iref.a.2"></span> <dfn>abstract privilege</dfn> <a class="self" href="#rfc.section.1.1.p.6">&para;</a></p><ul class="empty"><li>The modifier "abstract", when applied to a privilege on a resource, means the privilege cannot be set in an access control element (ACE) on that resource.</li></ul></div><div id="rfc.section.1.1.p.7"><p><span id="rfc.iref.a.3"></span> <span id="rfc.iref.a.4"></span> <dfn>access control list</dfn> (<dfn>ACL</dfn>) <a class="self" href="#rfc.section.1.1.p.7">&para;</a></p><ul class="empty"><li>An "ACL" is a list of access control elements that define access control to a particular resource.</li></ul></div><div id="rfc.section.1.1.p.8"><p><span id="rfc.iref.a.5"></span> <span id="rfc.iref.a.6"></span> <dfn>access control element</dfn> (<dfn>ACE</dfn>) <a class="self" href="#rfc.section.1.1.p.8">&para;</a></p><ul class="empty"><li>An "ACE" either grants or denies a particular set of (non-abstract) privileges for a particular principal.</li></ul></div><div id="rfc.section.1.1.p.9"><p><span id="rfc.iref.i.1"></span> <dfn>inherited ACE</dfn> <a class="self" href="#rfc.section.1.1.p.9">&para;</a></p><ul class="empty"><li>An "inherited ACE" is an ACE that is dynamically shared from the ACL of another resource. When a shared ACE changes on the primary resource, it is also changed on inheriting resources.</li></ul></div><div id="rfc.section.1.1.p.10"><p><span id="rfc.iref.p.3"></span> <dfn>protected property</dfn> <a class="self" href="#rfc.section.1.1.p.10">&para;</a></p><ul class="empty"><li>A "protected property" is one whose value cannot be updated except by a method explicitly defined as updating that specific property. In particular, a protected property cannot be updated with a PROPPATCH request.</li></ul></div></section><section id="n-notational-conventions"><h3 id="rfc.section.1.2"><a href="#rfc.section.1.2">1.2.</a>&nbsp;<a href="#n-notational-conventions">Notational Conventions</a></h3><div id="rfc.section.1.2.p.1"><p>The augmented BNF used by this document to describe protocol elements is described in <a href="https://tools.ietf.org/html/rfc2616#section-2.1">Section 2.1</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.2"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>. Because this augmented BNF uses the basic production rules provided in <a href="https://tools.ietf.org/html/rfc2616#section-2.2">Section 2.2</a> of <a href="#RFC2616" id="rfc.xref.RFC2616.3"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>, those rules apply to this document as well.<a class="self" href="#rfc.section.1.2.p.1">&para;</a></p></div><div id="rfc.section.1.2.p.2"><p>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in <a href="#RFC2119" id="rfc.xref.RFC2119.1"><cite title="Key words for use in RFCs to Indicate Requirement Levels">[RFC2119]</cite></a>.<a class="self" href="#rfc.section.1.2.p.2">&para;</a></p></div><div id="rfc.section.1.2.p.3"><p>Definitions of XML elements in this document use XML element type declarations (as found in XML Document Type Declarations), described in Section 3.2 of <a href="#REC-XML" id="rfc.xref.REC-XML.1"><cite title="Extensible Markup Language (XML) 1.0 (Third Edition)">[REC-XML]</cite></a>. When an XML element type in the "DAV:" namespace is referenced in this document outside of the context of an XML fragment, the string "DAV:" will be prefixed to the element name.<a class="self" href="#rfc.section.1.2.p.3">&para;</a></p></div></section></section><section id="principals"><h2 id="rfc.section.2"><a href="#rfc.section.2">2.</a>&nbsp;<a href="#principals">Principals</a></h2><div id="rfc.section.2.p.1"><p>A principal is a network resource that represents a distinct human or computational actor that initiates access to network resources. Users and groups are represented as principals in many implementations; other types of principals are also possible. A URI of any scheme <em class="bcp14">MAY</em> be used to identify a principal resource. However, servers implementing this specification <em class="bcp14">MUST</em> expose principal resources at an http(s) URL, which is a privileged scheme that points to resources that have additional properties, as described in <a href="#principal.properties" title="Principal Properties">Section&nbsp;4</a>. So, a principal resource can have multiple URIs, one of which has to be an http(s) scheme URL. Although an implementation <em class="bcp14">SHOULD</em> support PROPFIND and <em class="bcp14">MAY</em> support PROPPATCH to access and modify information about a principal, it is not required to do so.<a class="self" href="#rfc.section.2.p.1">&para;</a></p></div><div id="rfc.section.2.p.2"><p>A principal resource may be a group, where a group is a principal that represents a set of other principals, called the members of the group. If a person or computational agent matches a principal resource that is a member of a group, they also match the group. Membership in a group is recursive, so if a principal is a member of group GRPA, and GRPA is a member of group GRPB, then the principal is also a member of GRPB.<a class="self" href="#rfc.section.2.p.2">&para;</a></p></div></section><section id="privileges"><h2 id="rfc.section.3"><a href="#rfc.section.3">3.</a>&nbsp;<a href="#privileges">Privileges</a></h2><div id="rfc.section.3.p.1"><p>Ability to perform a given method on a resource <em class="bcp14">MUST</em> be controlled by one or more privileges. Authors of protocol extensions that define new HTTP methods <em class="bcp14">SHOULD</em> specify which privileges (by defining new privileges, or mapping to ones below) are required to perform the method. A principal with no privileges to a resource <em class="bcp14">MUST</em> be denied any HTTP access to that resource, unless the principal matches an ACE constructed using the DAV:all, DAV:authenticated, or DAV:unauthenticated pseudo-principals (see <a href="#ace.principal" title="ACE Principal">Section&nbsp;5.5.1</a>). Servers <em class="bcp14">MUST</em> report a 403 "Forbidden" error if access is denied, except in the case where the privilege restricts the ability to know the resource exists, in which case 404 "Not Found" may be returned.<a class="self" href="#rfc.section.3.p.1">&para;</a></p></div><div id="rfc.section.3.p.2"><p>Privileges may be containers of other privileges, in which case they are termed "aggregate privileges". If a principal is granted or denied an aggregate privilege, it is semantically equivalent to granting or denying each of the aggregated privileges individually. For example, an implementation may define add-member and remove-member privileges that control the ability to add and remove a member of a group. Since these privileges control the ability to update the state of a group, these privileges would be aggregated by the DAV:write privilege on a group, and granting the DAV:write privilege on a group would also grant the add-member and remove-member privileges.<a class="self" href="#rfc.section.3.p.2">&para;</a></p></div><div id="rfc.section.3.p.3"><p>Privileges may be declared to be "abstract" for a given resource, in which case they cannot be set in an ACE on that resource. Aggregate and non-aggregate privileges are both capable of being abstract. Abstract privileges are useful for modeling privileges that otherwise would not be exposed via the protocol. Abstract privileges also provide server implementations with flexibility in implementing the privileges defined in this specification. For example, if a server is incapable of separating the read resource capability from the read ACL capability, it can still model the DAV:read and DAV:read-acl privileges defined in this specification by declaring them abstract, and containing them within a non-abstract aggregate privilege (say, read-all) that holds DAV:read, and DAV:read-acl. In this way, it is possible to set the aggregate privilege, read-all, thus coupling the setting of DAV:read and DAV:read-acl, but it is not possible to set DAV:read, or DAV:read-acl individually. Since aggregate privileges can be abstract, it is also possible to use abstract privileges to group or organize non-abstract privileges. Privilege containment loops are not allowed; therefore, a privilege <em class="bcp14">MUST NOT</em> contain itself. For example, DAV:read cannot contain DAV:read.<a class="self" href="#rfc.section.3.p.3">&para;</a></p></div><div id="rfc.section.3.p.4"><p>The set of privileges that apply to a particular resource may vary with the DAV:resourcetype of the resource, as well as between different server implementations. To promote interoperability, however, this specification defines a set of well-known privileges (e.g., DAV:read, DAV:write, DAV:read-acl, DAV:write-acl, DAV:read-current-user-privilege-set, and DAV:all), which can at least be used to classify the other privileges defined on a particular resource. The access permissions on null resources (defined in <a href="#RFC2518" id="rfc.xref.RFC2518.2"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>, <a href="https://tools.ietf.org/html/rfc2518#section-3">Section 3</a>) are solely those they inherit (if any), and they are not discoverable (i.e., the access control properties specified in <a href="#access.control.properties" title="Access Control Properties">Section&nbsp;5</a> are not defined on null resources). On the transition from null to stateful resource, the initial access control list is set by the server's default ACL value policy (if any).<a class="self" href="#rfc.section.3.p.4">&para;</a></p></div><div id="rfc.section.3.p.5"><p>Server implementations <em class="bcp14">MAY</em> define new privileges beyond those defined in this specification. Privileges defined by individual implementations <em class="bcp14">MUST NOT</em> use the DAV: namespace, and instead should use a namespace that they control, such as an http scheme URL.<a class="self" href="#rfc.section.3.p.5">&para;</a></p></div><section id="PRIVILEGE_read"><h3 id="rfc.section.3.1"><a href="#rfc.section.3.1">3.1.</a>&nbsp;<a href="#PRIVILEGE_read">DAV:read Privilege</a></h3><div id="rfc.section.3.1.p.1"><p>The read privilege controls methods that return information about the state of the resource, including the resource's properties. Affected methods include GET and PROPFIND. Any implementation-defined privilege that also controls access to GET and PROPFIND must be aggregated under DAV:read - if an ACL grants access to DAV:read, the client may expect that no other privilege needs to be granted to have access to GET and PROPFIND. Additionally, the read privilege <em class="bcp14">MUST</em> control the OPTIONS method.<a class="self" href="#rfc.section.3.1.p.1">&para;</a></p></div><div id="rfc.figure.u.1"><pre class="inline">&lt;!ELEMENT read EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_write"><h3 id="rfc.section.3.2"><a href="#rfc.section.3.2">3.2.</a>&nbsp;<a href="#PRIVILEGE_write">DAV:write Privilege</a></h3><div id="rfc.section.3.2.p.1"><p>The write privilege controls methods that lock a resource or modify the content, dead properties, or (in the case of a collection) membership of the resource, such as PUT and PROPPATCH. Note that state modification is also controlled via locking (see <a href="https://tools.ietf.org/html/rfc2518#section-5.3">Section 5.3</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.3"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>), so effective write access requires that both write privileges and write locking requirements are satisfied. Any implementation-defined privilege that also controls access to methods modifying content, dead properties or collection membership must be aggregated under DAV:write, e.g., if an ACL grants access to DAV:write, the client may expect that no other privilege needs to be granted to have access to PUT and PROPPATCH.<a class="self" href="#rfc.section.3.2.p.1">&para;</a></p></div><div id="rfc.figure.u.2"><pre class="inline">&lt;!ELEMENT write EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_write-properties"><h3 id="rfc.section.3.3"><a href="#rfc.section.3.3">3.3.</a>&nbsp;<a href="#PRIVILEGE_write-properties">DAV:write-properties Privilege</a></h3><div id="rfc.section.3.3.p.1"><p>The DAV:write-properties privilege controls methods that modify the dead properties of the resource, such as PROPPATCH. Whether this privilege may be used to control access to any live properties is determined by the implementation. Any implementation-defined privilege that also controls access to methods modifying dead properties must be aggregated under DAV:write-properties - e.g., if an ACL grants access to DAV:write-properties, the client can safely expect that no other privilege needs to be granted to have access to PROPPATCH.<a class="self" href="#rfc.section.3.3.p.1">&para;</a></p></div><div id="rfc.figure.u.3"><pre class="inline">&lt;!ELEMENT write-properties EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_write-content"><h3 id="rfc.section.3.4"><a href="#rfc.section.3.4">3.4.</a>&nbsp;<a href="#PRIVILEGE_write-content">DAV:write-content Privilege</a></h3><div id="rfc.section.3.4.p.1"><p>The DAV:write-content privilege controls methods that modify the content of an existing resource, such as PUT. Any implementation-defined privilege that also controls access to content must be aggregated under DAV:write-content - e.g., if an ACL grants access to DAV:write-content, the client can safely expect that no other privilege needs to be granted to have access to PUT. Note that PUT - when applied to an unmapped URI - creates a new resource and therefore is controlled by the DAV:bind privilege on the parent collection.<a class="self" href="#rfc.section.3.4.p.1">&para;</a></p></div><div id="rfc.figure.u.4"><pre class="inline">&lt;!ELEMENT write-content EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_unlock"><h3 id="rfc.section.3.5"><a href="#rfc.section.3.5">3.5.</a>&nbsp;<a href="#PRIVILEGE_unlock">DAV:unlock Privilege</a></h3><div id="rfc.section.3.5.p.1"><p>The DAV:unlock privilege controls the use of the UNLOCK method by a principal other than the lock owner (the principal that created a lock can always perform an UNLOCK). While the set of users who may lock a resource is most commonly the same set of users who may modify a resource, servers may allow various kinds of administrators to unlock resources locked by others. Any privilege controlling access by non-lock owners to UNLOCK <em class="bcp14">MUST</em> be aggregated under DAV:unlock.<a class="self" href="#rfc.section.3.5.p.1">&para;</a></p></div><div id="rfc.section.3.5.p.2"><p>A lock owner can always remove a lock by issuing an UNLOCK with the correct lock token and authentication credentials. That is, even if a principal does not have DAV:unlock privilege, they can still remove locks they own. Principals other than the lock owner can remove a lock only if they have DAV:unlock privilege and they issue an UNLOCK with the correct lock token. Lock timeout is not affected by the DAV:unlock privilege.<a class="self" href="#rfc.section.3.5.p.2">&para;</a></p></div><div id="rfc.figure.u.5"><pre class="inline">&lt;!ELEMENT unlock EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_read-acl"><h3 id="rfc.section.3.6"><a href="#rfc.section.3.6">3.6.</a>&nbsp;<a href="#PRIVILEGE_read-acl">DAV:read-acl Privilege</a></h3><div id="rfc.section.3.6.p.1"><p>The DAV:read-acl privilege controls the use of PROPFIND to retrieve the DAV:acl property of the resource.<a class="self" href="#rfc.section.3.6.p.1">&para;</a></p></div><div id="rfc.figure.u.6"><pre class="inline">&lt;!ELEMENT read-acl EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_read-current-user-privilege-set"><h3 id="rfc.section.3.7"><a href="#rfc.section.3.7">3.7.</a>&nbsp;<a href="#PRIVILEGE_read-current-user-privilege-set">DAV:read-current-user-privilege-set Privilege</a></h3><div id="rfc.section.3.7.p.1"><p>The DAV:read-current-user-privilege-set privilege controls the use of PROPFIND to retrieve the DAV:current-user-privilege-set property of the resource.<a class="self" href="#rfc.section.3.7.p.1">&para;</a></p></div><div id="rfc.section.3.7.p.2"><p>Clients are intended to use this property to visually indicate in their UI items that are dependent on the permissions of a resource, for example, by graying out resources that are not writable.<a class="self" href="#rfc.section.3.7.p.2">&para;</a></p></div><div id="rfc.section.3.7.p.3"><p>This privilege is separate from DAV:read-acl because there is a need to allow most users access to the privileges permitted the current user (due to its use in creating the UI), while the full ACL contains information that may not be appropriate for the current authenticated user. As a result, the set of users who can view the full ACL is expected to be much smaller than those who can read the current user privilege set, and hence distinct privileges are needed for each.<a class="self" href="#rfc.section.3.7.p.3">&para;</a></p></div><div id="rfc.figure.u.7"><pre class="inline">&lt;!ELEMENT read-current-user-privilege-set EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_write-acl"><h3 id="rfc.section.3.8"><a href="#rfc.section.3.8">3.8.</a>&nbsp;<a href="#PRIVILEGE_write-acl">DAV:write-acl Privilege</a></h3><div id="rfc.section.3.8.p.1"><p>The DAV:write-acl privilege controls use of the ACL method to modify the DAV:acl property of the resource.<a class="self" href="#rfc.section.3.8.p.1">&para;</a></p></div><div id="rfc.figure.u.8"><pre class="inline">&lt;!ELEMENT write-acl EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_bind"><h3 id="rfc.section.3.9"><a href="#rfc.section.3.9">3.9.</a>&nbsp;<a href="#PRIVILEGE_bind">DAV:bind Privilege</a></h3><div id="rfc.section.3.9.p.1"><p>The DAV:bind privilege allows a method to add a new member URL to the specified collection (for example via PUT or MKCOL). It is ignored for resources that are not collections.<a class="self" href="#rfc.section.3.9.p.1">&para;</a></p></div><div id="rfc.figure.u.9"><pre class="inline">&lt;!ELEMENT bind EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_unbind"><h3 id="rfc.section.3.10"><a href="#rfc.section.3.10">3.10.</a>&nbsp;<a href="#PRIVILEGE_unbind">DAV:unbind Privilege</a></h3><div id="rfc.section.3.10.p.1"><p>The DAV:unbind privilege allows a method to remove a member URL from the specified collection (for example via DELETE or MOVE). It is ignored for resources that are not collections.<a class="self" href="#rfc.section.3.10.p.1">&para;</a></p></div><div id="rfc.figure.u.10"><pre class="inline">&lt;!ELEMENT unbind EMPTY&gt; 
</pre></div></section><section id="PRIVILEGE_all"><h3 id="rfc.section.3.11"><a href="#rfc.section.3.11">3.11.</a>&nbsp;<a href="#PRIVILEGE_all">DAV:all Privilege</a></h3><div id="rfc.section.3.11.p.1"><p>DAV:all is an aggregate privilege that contains the entire set of privileges that can be applied to the resource.<a class="self" href="#rfc.section.3.11.p.1">&para;</a></p></div><div id="rfc.figure.u.11"><pre class="inline">&lt;!ELEMENT all EMPTY&gt; 
</pre></div></section><section id="aggregation.of.predefined.privileges"><h3 id="rfc.section.3.12"><a href="#rfc.section.3.12">3.12.</a>&nbsp;<a href="#aggregation.of.predefined.privileges">Aggregation of Predefined Privileges</a></h3><div id="rfc.section.3.12.p.1" class="avoidbreakafter"><p>Server implementations are free to aggregate the predefined privileges (defined above in Sections <a href="#PRIVILEGE_read" title="DAV:read Privilege">3.1</a>-<a href="#PRIVILEGE_unbind" title="DAV:unbind Privilege">3.10</a>) subject to the following limitations:<a class="self" href="#rfc.section.3.12.p.1">&para;</a></p></div><div id="rfc.section.3.12.p.2"><p>DAV:read-acl <em class="bcp14">MUST NOT</em> contain DAV:read, DAV:write, DAV:write-acl, DAV:write-properties, DAV:write-content, or DAV:read-current-user-privilege-set.<a class="self" href="#rfc.section.3.12.p.2">&para;</a></p></div><div id="rfc.section.3.12.p.3"><p>DAV:write-acl <em class="bcp14">MUST NOT</em> contain DAV:write, DAV:read, DAV:read-acl, or DAV:read-current-user-privilege-set.<a class="self" href="#rfc.section.3.12.p.3">&para;</a></p></div><div id="rfc.section.3.12.p.4"><p>DAV:read-current-user-privilege-set <em class="bcp14">MUST NOT</em> contain DAV:write, DAV:read, DAV:read-acl, or DAV:write-acl.<a class="self" href="#rfc.section.3.12.p.4">&para;</a></p></div><div id="rfc.section.3.12.p.5"><p>DAV:write <em class="bcp14">MUST NOT</em> contain DAV:read, DAV:read-acl, or DAV:read-current-user-privilege-set.<a class="self" href="#rfc.section.3.12.p.5">&para;</a></p></div><div id="rfc.section.3.12.p.6"><p>DAV:read <em class="bcp14">MUST NOT</em> contain DAV:write, DAV:write-acl, DAV:write-properties, or DAV:write-content.<a class="self" href="#rfc.section.3.12.p.6">&para;</a></p></div><div id="rfc.section.3.12.p.7"><p>DAV:write <em class="bcp14">MUST</em> contain DAV:bind, DAV:unbind, DAV:write-properties and DAV:write-content.<a class="self" href="#rfc.section.3.12.p.7">&para;</a></p></div></section></section><section id="principal.properties"><h2 id="rfc.section.4"><a href="#rfc.section.4">4.</a>&nbsp;<a href="#principal.properties">Principal Properties</a></h2><div id="rfc.section.4.p.1" class="avoidbreakafter"><p>Principals are manifested to clients as a WebDAV resource, identified by a URL. A principal <em class="bcp14">MUST</em> have a non-empty DAV:displayname property (defined in <a href="https://tools.ietf.org/html/rfc2518#section-13.2">Section 13.2</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.4"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>), and a DAV:resourcetype property (defined in <a href="https://tools.ietf.org/html/rfc2518#section-13.9">Section 13.9</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.5"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>). Additionally, a principal <em class="bcp14">MUST</em> report the DAV:principal XML element in the value of the DAV:resourcetype property. The element type declaration for DAV:principal is:<a class="self" href="#rfc.section.4.p.1">&para;</a></p></div><div id="rfc.iref.d.1"></div><div id="rfc.iref.r.1"></div><div id="rfc.figure.u.12"><pre class="inline">&lt;!ELEMENT principal EMPTY&gt; 
</pre></div><div id="rfc.section.4.p.2"><p>This protocol defines the following additional properties for a principal. Since it can be expensive for a server to retrieve access control information, the name and value of these properties <em class="bcp14">SHOULD NOT</em> be returned by a PROPFIND allprop request (as defined in <a href="https://tools.ietf.org/html/rfc2518#section-12.14.1">Section 12.14.1</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.6"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>).<a class="self" href="#rfc.section.4.p.2">&para;</a></p></div><section id="PROPERTY_alternate-URI-set"><h3 id="rfc.section.4.1"><a href="#rfc.section.4.1">4.1.</a>&nbsp;<a href="#PROPERTY_alternate-URI-set">DAV:alternate-URI-set</a></h3><div id="rfc.section.4.1.p.1"><p>This protected property, if non-empty, contains the URIs of network resources with additional descriptive information about the principal. This property identifies additional network resources (i.e., it contains one or more URIs) that may be consulted by a client to gain additional knowledge concerning a principal. One expected use for this property is the storage of an LDAP <a href="#RFC2255" id="rfc.xref.RFC2255.1"><cite title="The LDAP URL Format">[RFC2255]</cite></a> scheme URL. A user-agent encountering an LDAP URL could use LDAP <a href="#RFC2251" id="rfc.xref.RFC2251.1"><cite title="Lightweight Directory Access Protocol (v3)">[RFC2251]</cite></a> to retrieve additional machine-readable directory information about the principal, and display that information in its user interface. Support for this property is <em class="bcp14">REQUIRED</em>, and the value is empty if no alternate URI exists for the principal.<a class="self" href="#rfc.section.4.1.p.1">&para;</a></p></div><div id="rfc.figure.u.13"><pre class="inline">&lt;!ELEMENT alternate-URI-set (href*)&gt; 
</pre></div></section><section id="PROPERTY_principal-URL"><h3 id="rfc.section.4.2"><a href="#rfc.section.4.2">4.2.</a>&nbsp;<a href="#PROPERTY_principal-URL">DAV:principal-URL</a></h3><div id="rfc.section.4.2.p.1"><p>A principal may have many URLs, but there must be one "principal URL" that clients can use to uniquely identify a principal. This protected property contains the URL that <em class="bcp14">MUST</em> be used to identify this principal in an ACL request. Support for this property is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.4.2.p.1">&para;</a></p></div><div id="rfc.figure.u.14"><pre class="inline">&lt;!ELEMENT principal-URL (href)&gt; 
</pre></div></section><section id="n-dav-group-member-set"><h3 id="rfc.section.4.3"><a href="#rfc.section.4.3">4.3.</a>&nbsp;<a href="#n-dav-group-member-set">DAV:group-member-set</a></h3><div id="rfc.section.4.3.p.1"><p>This property of a group principal identifies the principals that are direct members of this group. Since a group may be a member of another group, a group may also have indirect members (i.e., the members of its direct members). A URL in the DAV:group-member-set for a principal <em class="bcp14">MUST</em> be the DAV:principal-URL of that principal.<a class="self" href="#rfc.section.4.3.p.1">&para;</a></p></div><div id="rfc.figure.u.15"><pre class="inline">&lt;!ELEMENT group-member-set (href*)&gt; 
</pre></div></section><section id="n-dav-group-membership"><h3 id="rfc.section.4.4"><a href="#rfc.section.4.4">4.4.</a>&nbsp;<a href="#n-dav-group-membership">DAV:group-membership</a></h3><div id="rfc.section.4.4.p.1"><p>This protected property identifies the groups in which the principal is directly a member. Note that a server may allow a group to be a member of another group, in which case the DAV:group-membership of those other groups would need to be queried in order to determine the groups in which the principal is indirectly a member. Support for this property is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.4.4.p.1">&para;</a></p></div><div id="rfc.figure.u.16"><pre class="inline">&lt;!ELEMENT group-membership (href*)&gt; 
</pre></div></section></section><section id="access.control.properties"><h2 id="rfc.section.5"><a href="#rfc.section.5">5.</a>&nbsp;<a href="#access.control.properties">Access Control Properties</a></h2><div id="rfc.section.5.p.1"><p>This specification defines a number of new properties for WebDAV resources. Access control properties may be retrieved just like other WebDAV properties, using the PROPFIND method. Since it is expensive, for many servers, to retrieve access control information, a PROPFIND allprop request (as defined in <a href="https://tools.ietf.org/html/rfc2518#section-12.14.1">Section 12.14.1</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.7"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>) <em class="bcp14">SHOULD NOT</em> return the names and values of the properties defined in this section.<a class="self" href="#rfc.section.5.p.1">&para;</a></p></div><div id="rfc.section.5.p.2"><p>Access control properties (especially DAV:acl and DAV:inherited-acl-set) are defined on the resource identified by the Request-URI of a PROPFIND request. A direct consequence is that if the resource is accessible via multiple URI, the value of access control properties is the same across these URI.<a class="self" href="#rfc.section.5.p.2">&para;</a></p></div><div id="rfc.section.5.p.3"><p>HTTP resources that support the WebDAV Access Control Protocol <em class="bcp14">MUST</em> contain the following properties. Null resources (described in <a href="https://tools.ietf.org/html/rfc2518#section-3">Section 3</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.8"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>) <em class="bcp14">MUST NOT</em> contain the following properties.<a class="self" href="#rfc.section.5.p.3">&para;</a></p></div><section id="PROPERTY_owner"><h3 id="rfc.section.5.1"><a href="#rfc.section.5.1">5.1.</a>&nbsp;<a href="#PROPERTY_owner">DAV:owner</a></h3><div id="rfc.section.5.1.p.1"><p>This property identifies a particular principal as being the "owner" of the resource. Since the owner of a resource often has special access control capabilities (e.g., the owner frequently has permanent DAV:write-acl privilege), clients might display the resource owner in their user interface.<a class="self" href="#rfc.section.5.1.p.1">&para;</a></p></div><div id="rfc.section.5.1.p.2"><p>Servers <em class="bcp14">MAY</em> implement DAV:owner as protected property and <em class="bcp14">MAY</em> return an empty DAV:owner element as property value in case no owner information is available.<a class="self" href="#rfc.section.5.1.p.2">&para;</a></p></div><div id="rfc.figure.u.17"><pre class="inline">&lt;!ELEMENT owner (href?)&gt; 
</pre></div><section id="n-example--retrieving-dav-owner"><h4 id="rfc.section.5.1.1"><a href="#rfc.section.5.1.1">5.1.1.</a>&nbsp;<a href="#n-example--retrieving-dav-owner">Example: Retrieving DAV:owner</a></h4><div id="rfc.section.5.1.1.p.1"><p>This example shows a client request for the value of the DAV:owner property from a collection resource with URL http://www.example.com/papers/. The principal making the request is authenticated using Digest authentication. The value of DAV:owner is the URL http://www.example.com/acl/users/gstein, wrapped in the DAV:href XML element.<a class="self" href="#rfc.section.5.1.1.p.1">&para;</a></p></div><div id="rfc.figure.u.18"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="jim",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:owner/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.19"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:owner&gt; 
          &lt;D:href&gt;http://www.example.com/acl/users/gstein&lt;/D:href&gt;        
        &lt;/D:owner&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section><section id="n-example--an-attempt-to-set-dav-owner"><h4 id="rfc.section.5.1.2"><a href="#rfc.section.5.1.2">5.1.2.</a>&nbsp;<a href="#n-example--an-attempt-to-set-dav-owner">Example: An Attempt to Set DAV:owner</a></h4><div id="rfc.section.5.1.2.p.1"><p>The following example shows a client request to modify the value of the DAV:owner property on the resource with URL &lt;http://www.example.com/papers&gt;. Since DAV:owner is a protected property on this particular server, it responds with a 207 (Multi-Status) response that contains a 403 (Forbidden) status code for the act of setting DAV:owner. <a href="https://tools.ietf.org/html/rfc2518#section-8.2.1">Section 8.2.1</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.9"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a> describes PROPPATCH status code information, <a href="https://tools.ietf.org/html/rfc2518#section-11">Section 11</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.10"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a> describes the Multi-Status response and Sections <a href="https://tools.ietf.org/html/rfc3253#section-1.6" id="rfc.xref.RFC3253.1">1.6</a> and <a href="https://tools.ietf.org/html/rfc3253#section-3.12" id="rfc.xref.RFC3253.2">3.12</a> of <a href="#RFC3253" id="rfc.xref.RFC3253.3"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a> describe additional error marshaling for PROPPATCH attempts on protected properties.<a class="self" href="#rfc.section.5.1.2.p.1">&para;</a></p></div><div id="rfc.figure.u.20"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPPATCH /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="jim",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propertyupdate xmlns:D="DAV:"&gt; 
  &lt;D:set&gt; 
    &lt;D:prop&gt; 
      &lt;D:owner&gt; 
        &lt;D:href&gt;http://www.example.com/acl/users/jim&lt;/D:href&gt; 
      &lt;/D:owner&gt; 
    &lt;/D:prop&gt; 
  &lt;/D:set&gt; 
&lt;/D:propertyupdate&gt; 
</pre></div><div id="rfc.figure.u.21"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt;&lt;D:owner/&gt;&lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 403 Forbidden&lt;/D:status&gt; 
      &lt;D:responsedescription&gt;
        &lt;D:error&gt;&lt;D:cannot-modify-protected-property/&gt;&lt;/D:error&gt;
        Failure to set protected property (DAV:owner) 
      &lt;/D:responsedescription&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="PROPERTY_group"><h3 id="rfc.section.5.2"><a href="#rfc.section.5.2">5.2.</a>&nbsp;<a href="#PROPERTY_group">DAV:group</a></h3><div id="rfc.section.5.2.p.1"><p>This property identifies a particular principal as being the "group" of the resource. This property is commonly found on repositories that implement the Unix privileges model.<a class="self" href="#rfc.section.5.2.p.1">&para;</a></p></div><div id="rfc.section.5.2.p.2"><p>Servers <em class="bcp14">MAY</em> implement DAV:group as protected property and <em class="bcp14">MAY</em> return an empty DAV:group element as property value in case no group information is available.<a class="self" href="#rfc.section.5.2.p.2">&para;</a></p></div><div id="rfc.figure.u.22"><pre class="inline">&lt;!ELEMENT group (href?)&gt; 
</pre></div></section><section id="PROPERTY_supported-privilege-set"><h3 id="rfc.section.5.3"><a href="#rfc.section.5.3">5.3.</a>&nbsp;<a href="#PROPERTY_supported-privilege-set">DAV:supported-privilege-set</a></h3><div id="rfc.section.5.3.p.1"><p>This is a protected property that identifies the privileges defined for the resource.<a class="self" href="#rfc.section.5.3.p.1">&para;</a></p></div><div id="rfc.figure.u.23"><pre class="inline">&lt;!ELEMENT supported-privilege-set (supported-privilege*)&gt; 
</pre></div><div id="rfc.section.5.3.p.2"><p>Each privilege appears as an XML element, where aggregate privileges list as sub-elements all of the privileges that they aggregate.<a class="self" href="#rfc.section.5.3.p.2">&para;</a></p></div><div id="rfc.figure.u.24"><pre class="inline">&lt;!ELEMENT supported-privilege 
 (privilege, abstract?, description, supported-privilege*)&gt; 
&lt;!ELEMENT privilege ANY&gt; 
</pre></div><div id="rfc.section.5.3.p.3"><p>An abstract privilege <em class="bcp14">MUST NOT</em> be used in an ACE for that resource. Servers <em class="bcp14">MUST</em> fail an attempt to set an abstract privilege.<a class="self" href="#rfc.section.5.3.p.3">&para;</a></p></div><div id="rfc.figure.u.25"><pre class="inline">&lt;!ELEMENT abstract EMPTY&gt; 
</pre></div><div id="rfc.section.5.3.p.4"><p>A description is a human-readable description of what this privilege controls access to. Servers <em class="bcp14">MUST</em> indicate the human language of the description using the xml:lang attribute and <em class="bcp14">SHOULD</em> consider the HTTP Accept-Language request header when selecting one of multiple available languages.<a class="self" href="#rfc.section.5.3.p.4">&para;</a></p></div><div id="rfc.figure.u.26"><pre class="inline">&lt;!ELEMENT description #PCDATA&gt; 
</pre></div><div id="rfc.section.5.3.p.5"><p>It is envisioned that a WebDAV ACL-aware administrative client would list the supported privileges in a dialog box, and allow the user to choose non-abstract privileges to apply in an ACE. The privileges tree is useful programmatically to map well-known privileges (defined by WebDAV or other standards groups) into privileges that are supported by any particular server implementation. The privilege tree also serves to hide complexity in implementations allowing large number of privileges to be defined by displaying aggregates to the user.<a class="self" href="#rfc.section.5.3.p.5">&para;</a></p></div><section id="example.retrieving.a.list.of.privileges.supported.on.a.resource"><h4 id="rfc.section.5.3.1"><a href="#rfc.section.5.3.1">5.3.1.</a>&nbsp;<a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource">Example: Retrieving a List of Privileges Supported on a Resource</a></h4><div id="rfc.section.5.3.1.p.1" class="avoidbreakafter"><p>This example shows a client request for the DAV:supported-privilege-set property on the resource http://www.example.com/papers/. The value of the DAV:supported-privilege-set property is a tree of supported privileges (using "[XML Namespace , localname]" to identify each privilege):<a class="self" href="#rfc.section.5.3.1.p.1">&para;</a></p></div><div id="rfc.figure.u.27"><pre class="drawing">[DAV:, all] (aggregate, abstract) 
   &#9474;
   &#9492;&#9472;&#9472; [DAV:, read] (aggregate) 
          &#9474; 
          &#9500;&#9472;&#9472; [DAV:, read-acl] (abstract) 
          &#9492;&#9472;&#9472; [DAV:, read-current-user-privilege-set] (abstract) 
   &#9474; 
   &#9492;&#9472;&#9472; [DAV:, write] (aggregate) 
          &#9474; 
          &#9500;&#9472;&#9472; [DAV:, write-acl] (abstract) 
          &#9500;&#9472;&#9472; [DAV:, write-properties] 
          &#9492;&#9472;&#9472; [DAV:, write-content] 
   &#9474;
   &#9492;&#9472;&#9472; [DAV:, unlock]  
</pre></div><div id="rfc.section.5.3.1.p.2"><p>This privilege tree is not normative (except that it reflects the normative aggregation rules given in <a href="#aggregation.of.predefined.privileges" title="Aggregation of Predefined Privileges">Section&nbsp;3.12</a>), and many possible privilege trees are possible.<a class="self" href="#rfc.section.5.3.1.p.2">&para;</a></p></div><div id="rfc.figure.u.28"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="gclemm",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:supported-privilege-set/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.29"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt;
&lt;D:multistatus xmlns:D="DAV:"&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt;
    &lt;D:propstat&gt;
      &lt;D:prop&gt;
        &lt;D:supported-privilege-set&gt;
          &lt;D:supported-privilege&gt;
            &lt;D:privilege&gt;&lt;D:all/&gt;&lt;/D:privilege&gt;
           &lt;D:abstract/&gt;
            &lt;D:description xml:lang="en"&gt;
              Any operation
            &lt;/D:description&gt;
            &lt;D:supported-privilege&gt;
              &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;
              &lt;D:description xml:lang="en"&gt;
                Read any object
              &lt;/D:description&gt;
              &lt;D:supported-privilege&gt;
                &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt;
                &lt;D:abstract/&gt;
                &lt;D:description xml:lang="en"&gt;Read ACL&lt;/D:description&gt;
              &lt;/D:supported-privilege&gt;
              &lt;D:supported-privilege&gt;
                &lt;D:privilege&gt; 
                  &lt;D:read-current-user-privilege-set/&gt;
                &lt;/D:privilege&gt;
                &lt;D:abstract/&gt;
                &lt;D:description xml:lang="en"&gt;
                  Read current user privilege set property
                &lt;/D:description&gt;
              &lt;/D:supported-privilege&gt;
            &lt;/D:supported-privilege&gt;
            &lt;D:supported-privilege&gt;
              &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt;
              &lt;D:description xml:lang="en"&gt;
                Write any object
              &lt;/D:description&gt;
              &lt;D:supported-privilege&gt;
                &lt;D:privilege&gt;&lt;D:write-acl/&gt;&lt;/D:privilege&gt;
                &lt;D:description xml:lang="en"&gt;
                  Write ACL
                &lt;/D:description&gt;
                &lt;D:abstract/&gt;
              &lt;/D:supported-privilege&gt;
              &lt;D:supported-privilege&gt;
                &lt;D:privilege&gt;&lt;D:write-properties/&gt;&lt;/D:privilege&gt;
                &lt;D:description xml:lang="en"&gt;
                  Write properties
                &lt;/D:description&gt;
              &lt;/D:supported-privilege&gt;
              &lt;D:supported-privilege&gt;
                &lt;D:privilege&gt;&lt;D:write-content/&gt;&lt;/D:privilege&gt;
                &lt;D:description xml:lang="en"&gt;
                  Write resource content
                &lt;/D:description&gt;
              &lt;/D:supported-privilege&gt;
            &lt;/D:supported-privilege&gt;
            &lt;D:supported-privilege&gt;
              &lt;D:privilege&gt;&lt;D:unlock/&gt;&lt;/D:privilege&gt;
              &lt;D:description xml:lang="en"&gt;
                Unlock resource
              &lt;/D:description&gt;
            &lt;/D:supported-privilege&gt;
          &lt;/D:supported-privilege&gt;
        &lt;/D:supported-privilege-set&gt;
      &lt;/D:prop&gt;
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt;
    &lt;/D:propstat&gt;
  &lt;/D:response&gt;
&lt;/D:multistatus&gt;
</pre></div></section></section><section id="PROPERTY_current-user-privilege-set"><h3 id="rfc.section.5.4"><a href="#rfc.section.5.4">5.4.</a>&nbsp;<a href="#PROPERTY_current-user-privilege-set">DAV:current-user-privilege-set</a></h3><div id="rfc.section.5.4.p.1"><p>DAV:current-user-privilege-set is a protected property containing the exact set of privileges (as computed by the server) granted to the currently authenticated HTTP user. Aggregate privileges and their contained privileges are listed. A user-agent can use the value of this property to adjust its user interface to make actions inaccessible (e.g., by graying out a menu item or button) for which the current principal does not have permission. This property is also useful for determining what operations the current principal can perform, without having to actually execute an operation.<a class="self" href="#rfc.section.5.4.p.1">&para;</a></p></div><div id="rfc.figure.u.30"><pre class="inline">&lt;!ELEMENT current-user-privilege-set (privilege*)&gt; 
&lt;!ELEMENT privilege ANY&gt; 
</pre></div><div id="rfc.section.5.4.p.2"><p>If the current user is granted a specific privilege, that privilege must belong to the set of privileges that may be set on this resource. Therefore, each element in the DAV:current-user-privilege-set property <em class="bcp14">MUST</em> identify a non-abstract privilege from the DAV:supported-privilege-set property.<a class="self" href="#rfc.section.5.4.p.2">&para;</a></p></div><section id="example.retrieving.the.users.current.set.of.assigned.privileges"><h4 id="rfc.section.5.4.1"><a href="#rfc.section.5.4.1">5.4.1.</a>&nbsp;<a href="#example.retrieving.the.users.current.set.of.assigned.privileges">Example: Retrieving the User's Current Set of Assigned Privileges</a></h4><div id="rfc.section.5.4.1.p.1"><p>Continuing the example from <a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource" title="Example: Retrieving a List of Privileges Supported on a Resource">Section&nbsp;5.3.1</a>, this example shows a client requesting the DAV:current-user-privilege-set property from the resource with URL http://www.example.com/papers/. The username of the principal making the request is "khare", and Digest authentication is used in the request. The principal with username "khare" has been granted the DAV:read privilege. Since the DAV:read privilege contains the DAV:read-acl and DAV:read-current-user-privilege-set privileges (see <a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource" title="Example: Retrieving a List of Privileges Supported on a Resource">Section&nbsp;5.3.1</a>), the principal with username "khare" can read the ACL property, and the DAV:current-user-privilege-set property. However, the DAV:all, DAV:read-acl, DAV:write-acl and DAV:read-current-user-privilege-set privileges are not listed in the value of DAV:current-user-privilege-set, since (for this example) they are abstract privileges. DAV:write is not listed since the principal with username "khare" is not listed in an ACE granting that principal write permission.<a class="self" href="#rfc.section.5.4.1.p.1">&para;</a></p></div><div id="rfc.figure.u.31"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="khare",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:current-user-privilege-set/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.32"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
  &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
  &lt;D:propstat&gt; 
    &lt;D:prop&gt; 
      &lt;D:current-user-privilege-set&gt; 
        &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
      &lt;/D:current-user-privilege-set&gt; 
    &lt;/D:prop&gt; 
    &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
  &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="PROPERTY_acl"><h3 id="rfc.section.5.5"><a href="#rfc.section.5.5">5.5.</a>&nbsp;<a href="#PROPERTY_acl">DAV:acl</a></h3><div id="rfc.section.5.5.p.1"><p>This is a protected property that specifies the list of access control entries (ACEs), which define what principals are to get what privileges for this resource.<a class="self" href="#rfc.section.5.5.p.1">&para;</a></p></div><div id="rfc.figure.u.33"><pre class="inline">&lt;!ELEMENT acl (ace*) &gt; 
</pre></div><div id="rfc.section.5.5.p.2"><p>Each DAV:ace element specifies the set of privileges to be either granted or denied to a single principal. If the DAV:acl property is empty, no principal is granted any privilege.<a class="self" href="#rfc.section.5.5.p.2">&para;</a></p></div><div id="rfc.figure.u.34"><pre class="inline">&lt;!ELEMENT ace ((principal | invert), (grant|deny), protected?,
               inherited?)&gt; 
</pre></div><section id="ace.principal"><h4 id="rfc.section.5.5.1"><a href="#rfc.section.5.5.1">5.5.1.</a>&nbsp;<a href="#ace.principal">ACE Principal</a></h4><div id="rfc.section.5.5.1.p.1"><p>The DAV:principal element identifies the principal to which this ACE applies.<a class="self" href="#rfc.section.5.5.1.p.1">&para;</a></p></div><div id="rfc.figure.u.35"><pre class="inline">&lt;!ELEMENT principal (href | all | authenticated | unauthenticated 
 | property | self)&gt; 
</pre></div><div id="rfc.section.5.5.1.p.2"><p>The current user matches DAV:href only if that user is authenticated as being (or being a member of) the principal identified by the URL contained by that DAV:href.<a class="self" href="#rfc.section.5.5.1.p.2">&para;</a></p></div><div id="rfc.section.5.5.1.p.3"><p>The current user always matches DAV:all.<a class="self" href="#rfc.section.5.5.1.p.3">&para;</a></p></div><div id="rfc.figure.u.36"><pre class="inline">&lt;!ELEMENT all EMPTY&gt; 
</pre></div><div id="rfc.section.5.5.1.p.4"><p>The current user matches DAV:authenticated only if authenticated.<a class="self" href="#rfc.section.5.5.1.p.4">&para;</a></p></div><div id="rfc.figure.u.37"><pre class="inline">&lt;!ELEMENT authenticated EMPTY&gt; 
</pre></div><div id="rfc.section.5.5.1.p.5"><p>The current user matches DAV:unauthenticated only if not authenticated.<a class="self" href="#rfc.section.5.5.1.p.5">&para;</a></p></div><div id="rfc.figure.u.38"><pre class="inline">&lt;!ELEMENT unauthenticated EMPTY&gt; 
</pre></div><div id="rfc.section.5.5.1.p.6"><p>DAV:all is the union of DAV:authenticated, and DAV:unauthenticated. For a given request, the user matches either DAV:authenticated, or DAV:unauthenticated, but not both (that is, DAV:authenticated and DAV:unauthenticated are disjoint sets).<a class="self" href="#rfc.section.5.5.1.p.6">&para;</a></p></div><div id="rfc.section.5.5.1.p.7"><p>The current user matches a DAV:property principal in a DAV:acl property of a resource only if the value of the identified property of that resource contains at most one DAV:href XML element, the URI value of DAV:href identifies a principal, and the current user is authenticated as being (or being a member of) that principal. For example, if the DAV:property element contained &lt;DAV:owner/&gt;, the current user would match the DAV:property principal only if the current user is authenticated as matching the principal identified by the DAV:owner property of the resource.<a class="self" href="#rfc.section.5.5.1.p.7">&para;</a></p></div><div id="rfc.figure.u.39"><pre class="inline">&lt;!ELEMENT property ANY&gt; 
</pre></div><div id="rfc.section.5.5.1.p.8"><p>The current user matches DAV:self in a DAV:acl property of the resource only if that resource is a principal and that principal matches the current user or, if the principal is a group, a member of that group matches the current user.<a class="self" href="#rfc.section.5.5.1.p.8">&para;</a></p></div><div id="rfc.figure.u.40"><pre class="inline">&lt;!ELEMENT self EMPTY&gt; 
</pre></div><div id="rfc.section.5.5.1.p.9"><p>Some servers may support ACEs applying to those users NOT matching the current principal, e.g., all users not in a particular group. This can be done by wrapping the DAV:principal element with DAV:invert.<a class="self" href="#rfc.section.5.5.1.p.9">&para;</a></p></div><div id="rfc.figure.u.41"><pre class="inline">&lt;!ELEMENT invert principal&gt; 
</pre></div></section><section id="n-ace-grant-and-deny"><h4 id="rfc.section.5.5.2"><a href="#rfc.section.5.5.2">5.5.2.</a>&nbsp;<a href="#n-ace-grant-and-deny">ACE Grant and Deny</a></h4><div id="rfc.section.5.5.2.p.1"><p>Each DAV:grant or DAV:deny element specifies the set of privileges to be either granted or denied to the specified principal. A DAV:grant or DAV:deny element of the DAV:acl of a resource <em class="bcp14">MUST</em> only contain non-abstract elements specified in the DAV:supported-privilege-set of that resource.<a class="self" href="#rfc.section.5.5.2.p.1">&para;</a></p></div><div id="rfc.figure.u.42"><pre class="inline">&lt;!ELEMENT grant (privilege+)&gt; 
&lt;!ELEMENT deny (privilege+)&gt; 
&lt;!ELEMENT privilege ANY&gt; 
</pre></div></section><section id="ace.protection"><h4 id="rfc.section.5.5.3"><a href="#rfc.section.5.5.3">5.5.3.</a>&nbsp;<a href="#ace.protection">ACE Protection</a></h4><div id="rfc.section.5.5.3.p.1"><p>A server indicates an ACE is protected by including the DAV:protected element in the ACE. If the ACL of a resource contains an ACE with a DAV:protected element, an attempt to remove that ACE from the ACL <em class="bcp14">MUST</em> fail.<a class="self" href="#rfc.section.5.5.3.p.1">&para;</a></p></div><div id="rfc.figure.u.43"><pre class="inline">&lt;!ELEMENT protected EMPTY&gt; 
</pre></div></section><section id="n-ace-inheritance"><h4 id="rfc.section.5.5.4"><a href="#rfc.section.5.5.4">5.5.4.</a>&nbsp;<a href="#n-ace-inheritance">ACE Inheritance</a></h4><div id="rfc.section.5.5.4.p.1"><p>The presence of a DAV:inherited element indicates that this ACE is inherited from another resource that is identified by the URL contained in a DAV:href element. An inherited ACE cannot be modified directly, but instead the ACL on the resource from which it is inherited must be modified.<a class="self" href="#rfc.section.5.5.4.p.1">&para;</a></p></div><div id="rfc.section.5.5.4.p.2"><p>Note that ACE inheritance is not the same as ACL initialization. ACL initialization defines the ACL that a newly created resource will use (if not specified). ACE inheritance refers to an ACE that is logically shared - where an update to the resource containing an ACE will affect the ACE of each resource that inherits that ACE. The method by which ACLs are initialized or by which ACEs are inherited is not defined by this document.<a class="self" href="#rfc.section.5.5.4.p.2">&para;</a></p></div><div id="rfc.figure.u.44"><pre class="inline">&lt;!ELEMENT inherited (href)&gt; 
</pre></div></section><section><h4 id="rfc.section.5.5.5"><a href="#rfc.section.5.5.5">5.5.5.</a>&nbsp;Example: Retrieving a Resource's Access Control List</h4><div id="rfc.section.5.5.5.p.1" class="avoidbreakafter"><p>Continuing the example from Sections <a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource" title="Example: Retrieving a List of Privileges Supported on a Resource">5.3.1</a> and <a href="#example.retrieving.the.users.current.set.of.assigned.privileges" title="Example: Retrieving the User's Current Set of Assigned Privileges">5.4.1</a>, this example shows a client requesting the DAV:acl property from the resource with URL http://www.example.com/papers/. There are two ACEs defined in this ACL:<a class="self" href="#rfc.section.5.5.5.p.1">&para;</a></p></div><div id="rfc.section.5.5.5.p.2"><p>ACE #1: The group identified by URL http://www.example.com/acl/groups/maintainers (the group of site maintainers) is granted DAV:write privilege. Since (for this example) DAV:write contains the DAV:write-acl privilege (see <a href="#example.retrieving.a.list.of.privileges.supported.on.a.resource" title="Example: Retrieving a List of Privileges Supported on a Resource">Section&nbsp;5.3.1</a>), this means the "maintainers" group can also modify the access control list.<a class="self" href="#rfc.section.5.5.5.p.2">&para;</a></p></div><div id="rfc.section.5.5.5.p.3"><p>ACE #2: All principals (DAV:all) are granted the DAV:read privilege. Since (for this example) DAV:read contains DAV:read-acl and DAV:read-current-user-privilege-set, this means all users (including all members of the "maintainers" group) can read the DAV:acl property and the DAV:current-user-privilege-set property.<a class="self" href="#rfc.section.5.5.5.p.3">&para;</a></p></div><div id="rfc.figure.u.45"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="masinter",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:acl/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.46"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:acl&gt; 
        &lt;D:ace&gt; 
          &lt;D:principal&gt; 
            &lt;D:href
            &gt;http://www.example.com/acl/groups/maintainers&lt;/D:href&gt; 
          &lt;/D:principal&gt;  
          &lt;D:grant&gt; 
            &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt; 
          &lt;/D:grant&gt; 
        &lt;/D:ace&gt; 
        &lt;D:ace&gt; 
          &lt;D:principal&gt; 
            &lt;D:all/&gt; 
          &lt;/D:principal&gt; 
          &lt;D:grant&gt; 
            &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;  
          &lt;/D:grant&gt; 
        &lt;/D:ace&gt; 
      &lt;/D:acl&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt;
</pre></div></section></section><section id="PROPERTY_acl-restrictions"><h3 id="rfc.section.5.6"><a href="#rfc.section.5.6">5.6.</a>&nbsp;<a href="#PROPERTY_acl-restrictions">DAV:acl-restrictions</a></h3><div id="rfc.section.5.6.p.1"><p>This protected property defines the types of ACLs supported by this server, to avoid clients needlessly getting errors. When a client tries to set an ACL via the ACL method, the server may reject the attempt to set the ACL as specified. The following properties indicate the restrictions the client must observe before setting an ACL: <a class="self" href="#rfc.section.5.6.p.1">&para;</a></p><dl><dt>&lt;grant-only&gt;</dt><dd>Deny ACEs are not supported</dd><dt>&lt;no-invert&gt;</dt><dd>Inverted ACEs are not supported</dd><dt>&lt;deny-before-grant&gt;</dt><dd>All deny ACEs must occur before any grant ACEs</dd><dt>&lt;required-principal&gt;</dt><dd>Indicates which principals are required to be present</dd></dl></div><div id="rfc.figure.u.47"><pre class="inline">&lt;!ELEMENT acl-restrictions (grant-only?, no-invert?, 
                            deny-before-grant?,
                            required-principal?)&gt; 
</pre></div><section id="RESTRICTIONS_grant-only"><h4 id="rfc.section.5.6.1"><a href="#rfc.section.5.6.1">5.6.1.</a>&nbsp;<a href="#RESTRICTIONS_grant-only">DAV:grant-only</a></h4><div id="rfc.section.5.6.1.p.1"><p>This element indicates that ACEs with deny clauses are not allowed.<a class="self" href="#rfc.section.5.6.1.p.1">&para;</a></p></div><div id="rfc.figure.u.48"><pre class="inline">&lt;!ELEMENT grant-only EMPTY&gt; 
</pre></div></section><section id="CONSTRAINT_no-invert"><h4 id="rfc.section.5.6.2"><a href="#rfc.section.5.6.2">5.6.2.</a>&nbsp;<a href="#CONSTRAINT_no-invert">DAV:no-invert ACE Constraint</a></h4><div id="rfc.section.5.6.2.p.1"><p>This element indicates that ACEs with the &lt;invert&gt; element are not allowed.<a class="self" href="#rfc.section.5.6.2.p.1">&para;</a></p></div><div id="rfc.figure.u.49"><pre class="inline">&lt;!ELEMENT no-invert EMPTY&gt; 
</pre></div></section><section id="n-dav-deny-before-grant"><h4 id="rfc.section.5.6.3"><a href="#rfc.section.5.6.3">5.6.3.</a>&nbsp;<a href="#n-dav-deny-before-grant">DAV:deny-before-grant</a></h4><div id="rfc.section.5.6.3.p.1"><p>This element indicates that all deny ACEs must precede all grant ACEs.<a class="self" href="#rfc.section.5.6.3.p.1">&para;</a></p></div><div id="rfc.figure.u.50"><pre class="inline">&lt;!ELEMENT deny-before-grant EMPTY&gt; 
</pre></div></section><section id="n-required-principals"><h4 id="rfc.section.5.6.4"><a href="#rfc.section.5.6.4">5.6.4.</a>&nbsp;<a href="#n-required-principals">Required Principals</a></h4><div id="rfc.section.5.6.4.p.1"><p>The required principal elements identify which principals must have an ACE defined in the ACL.<a class="self" href="#rfc.section.5.6.4.p.1">&para;</a></p></div><div id="rfc.figure.u.51"><pre class="inline">&lt;!ELEMENT required-principal 
  (all? | authenticated? | unauthenticated? | self? | href* |
   property*)&gt; 
</pre></div><div id="rfc.section.5.6.4.p.2" class="avoidbreakafter"><p>For example, the following element requires that the ACL contain a DAV:owner property ACE:<a class="self" href="#rfc.section.5.6.4.p.2">&para;</a></p></div><div id="rfc.figure.u.52"><pre class="inline">&lt;D:required-principal xmlns:D="DAV:"&gt; 
  &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt; 
&lt;/D:required-principal&gt; 
</pre></div></section><section id="n-example--retrieving-dav-acl-restrictions"><h4 id="rfc.section.5.6.5"><a href="#rfc.section.5.6.5">5.6.5.</a>&nbsp;<a href="#n-example--retrieving-dav-acl-restrictions">Example: Retrieving DAV:acl-restrictions</a></h4><div id="rfc.section.5.6.5.p.1"><p>In this example, the client requests the value of the DAV:acl-restrictions property. Digest authentication provides credentials for the principal operating the client.<a class="self" href="#rfc.section.5.6.5.p.1">&para;</a></p></div><div id="rfc.figure.u.53"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="srcarter",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:acl-restrictions/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.54"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:acl-restrictions&gt; 
          &lt;D:grant-only/&gt; 
          &lt;D:required-principal&gt; 
            &lt;D:all/&gt; 
          &lt;/D:required-principal&gt; 
        &lt;/D:acl-restrictions&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt;
</pre></div></section></section><section id="PROPERTY_inherited-acl-set"><h3 id="rfc.section.5.7"><a href="#rfc.section.5.7">5.7.</a>&nbsp;<a href="#PROPERTY_inherited-acl-set">DAV:inherited-acl-set</a></h3><div id="rfc.section.5.7.p.1"><p>This protected property contains a set of URLs that identify other resources that also control the access to this resource. To have a privilege on a resource, not only must the ACL on that resource (specified in the DAV:acl property of that resource) grant the privilege, but so must the ACL of each resource identified in the DAV:inherited-acl-set property of that resource. Effectively, the privileges granted by the current ACL are ANDed with the privileges granted by each inherited ACL.<a class="self" href="#rfc.section.5.7.p.1">&para;</a></p></div><div id="rfc.figure.u.55"><pre class="inline">&lt;!ELEMENT inherited-acl-set (href*)&gt; 
</pre></div></section><section id="PROPERTY_principal-collection-set"><h3 id="rfc.section.5.8"><a href="#rfc.section.5.8">5.8.</a>&nbsp;<a href="#PROPERTY_principal-collection-set">DAV:principal-collection-set</a></h3><div id="rfc.section.5.8.p.1"><p>This protected property of a resource contains a set of URLs that identify the root collections that contain the principals that are available on the server that implements this resource. A WebDAV Access Control Protocol user agent could use the contents of DAV:principal-collection-set to retrieve the DAV:displayname property (specified in <a href="https://tools.ietf.org/html/rfc2518#section-13.2">Section 13.2</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.11"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>) of all principals on that server, thereby yielding human-readable names for each principal that could be displayed in a user interface.<a class="self" href="#rfc.section.5.8.p.1">&para;</a></p></div><div id="rfc.figure.u.56"><pre class="inline">&lt;!ELEMENT principal-collection-set (href*)&gt; 
</pre></div><div id="rfc.section.5.8.p.2"><p>Since different servers can control different parts of the URL namespace, different resources on the same host <em class="bcp14">MAY</em> have different DAV:principal-collection-set values. The collections specified in the DAV:principal-collection-set <em class="bcp14">MAY</em> be located on different hosts from the resource. The URLs in DAV:principal-collection-set <em class="bcp14">SHOULD</em> be http or https scheme URLs. For security and scalability reasons, a server <em class="bcp14">MAY</em> report only a subset of the entire set of known principal collections, and therefore clients should not assume they have retrieved an exhaustive listing. Additionally, a server <em class="bcp14">MAY</em> elect to report none of the principal collections it knows about, in which case the property value would be empty.<a class="self" href="#rfc.section.5.8.p.2">&para;</a></p></div><div id="rfc.section.5.8.p.3"><p>The value of DAV:principal-collection-set gives the scope of the DAV:principal-property-search REPORT (defined in <a href="#REPORT_principal-property-search" title="DAV:principal-property-search REPORT">Section&nbsp;9.4</a>). Clients use the DAV:principal-property-search REPORT to populate their user interface with a list of principals. Therefore, servers that limit a client's ability to obtain principal information will interfere with the client's ability to manipulate access control lists, due to the difficulty of getting the URL of a principal for use in an ACE.<a class="self" href="#rfc.section.5.8.p.3">&para;</a></p></div><section id="n-example--retrieving-dav-principal-collection-set"><h4 id="rfc.section.5.8.1"><a href="#rfc.section.5.8.1">5.8.1.</a>&nbsp;<a href="#n-example--retrieving-dav-principal-collection-set">Example: Retrieving DAV:principal-collection-set</a></h4><div id="rfc.section.5.8.1.p.1"><p>In this example, the client requests the value of the DAV:principal-collection-set property on the collection resource identified by URL http://www.example.com/papers/. The property contains the two URLs, http://www.example.com/acl/users/ and http://www.example.com/acl/groups/, both wrapped in DAV:href XML elements. Digest authentication provides credentials for the principal operating the client.<a class="self" href="#rfc.section.5.8.1.p.1">&para;</a></p></div><div id="rfc.section.5.8.1.p.2"><p>The client might reasonably follow this request with two separate PROPFIND requests to retrieve the DAV:displayname property of the members of the two collections (/acl/users and /acl/groups). This information could be used when displaying a user interface for creating access control entries.<a class="self" href="#rfc.section.5.8.1.p.2">&para;</a></p></div><div id="rfc.figure.u.57"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /papers/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="yarong",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:principal-collection-set/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.58"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt;  
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/papers/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:principal-collection-set&gt; 
          &lt;D:href&gt;http://www.example.com/acl/users/&lt;/D:href&gt; 
          &lt;D:href&gt;http://www.example.com/acl/groups/&lt;/D:href&gt; 
        &lt;/D:principal-collection-set&gt; 
      &lt;/D:prop&gt; 
    &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="n-example--propfind-to-retrieve-access-control-properties"><h3 id="rfc.section.5.9"><a href="#rfc.section.5.9">5.9.</a>&nbsp;<a href="#n-example--propfind-to-retrieve-access-control-properties">Example: PROPFIND to retrieve access control properties</a></h3><div id="rfc.section.5.9.p.1"><p>The following example shows how access control information can be retrieved by using the PROPFIND method to fetch the values of the DAV:owner, DAV:supported-privilege-set, DAV:current-user-privilege-set, and DAV:acl properties.<a class="self" href="#rfc.section.5.9.p.1">&para;</a></p></div><div id="rfc.figure.u.59"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">PROPFIND /top/container/ HTTP/1.1 
Host: www.example.com 
Content-type: text/xml; charset="utf-8"  
Content-Length: xxx 
Depth: 0 
Authorization: Digest username="ejw",  
  realm="users@example.com", nonce="...", 
  uri="/top/container/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:propfind xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:owner/&gt; 
    &lt;D:supported-privilege-set/&gt; 
    &lt;D:current-user-privilege-set/&gt; 
    &lt;D:acl/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:propfind&gt; 
</pre></div><div id="rfc.figure.u.60"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:" 
               xmlns:A="http://www.example.com/acl/"&gt;
  &lt;D:response&gt;  
    &lt;D:href&gt;http://www.example.com/top/container/&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:owner&gt; 
          &lt;D:href&gt;http://www.example.com/users/gclemm&lt;/D:href&gt; 
        &lt;/D:owner&gt; 
        &lt;D:supported-privilege-set&gt; 
          &lt;D:supported-privilege&gt; 
            &lt;D:privilege&gt;&lt;D:all/&gt;&lt;/D:privilege&gt; 
            &lt;D:abstract/&gt; 
            &lt;D:description xml:lang="en"&gt;
              Any operation
            &lt;/D:description&gt; 
            &lt;D:supported-privilege&gt; 
              &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
              &lt;D:description xml:lang="en"&gt;
                Read any object
              &lt;/D:description&gt; 
            &lt;/D:supported-privilege&gt; 
            &lt;D:supported-privilege&gt; 
              &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt; 
              &lt;D:abstract/&gt; 
              &lt;D:description xml:lang="en"&gt;
                Write any object
              &lt;/D:description&gt; 
              &lt;D:supported-privilege&gt; 
                &lt;D:privilege&gt;&lt;A:create/&gt;&lt;/D:privilege&gt; 
                &lt;D:description xml:lang="en"&gt;
                  Create an object
                &lt;/D:description&gt; 
              &lt;/D:supported-privilege&gt; 
              &lt;D:supported-privilege&gt; 
                &lt;D:privilege&gt;&lt;A:update/&gt;&lt;/D:privilege&gt; 
                &lt;D:description xml:lang="en"&gt;
                  Update an object
                &lt;/D:description&gt; 
              &lt;/D:supported-privilege&gt; 
            &lt;/D:supported-privilege&gt; 
            &lt;D:supported-privilege&gt;
              &lt;D:privilege&gt;&lt;A:delete/&gt;&lt;/D:privilege&gt;
              &lt;D:description xml:lang="en"&gt;
                Delete an object
              &lt;/D:description&gt;
            &lt;/D:supported-privilege&gt;
            &lt;D:supported-privilege&gt; 
              &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt; 
              &lt;D:description xml:lang="en"&gt;
                Read the ACL
              &lt;/D:description&gt; 
            &lt;/D:supported-privilege&gt; 
            &lt;D:supported-privilege&gt; 
              &lt;D:privilege&gt;&lt;D:write-acl/&gt;&lt;/D:privilege&gt; 
              &lt;D:description xml:lang="en"&gt;
                Write the ACL
              &lt;/D:description&gt; 
            &lt;/D:supported-privilege&gt; 
          &lt;/D:supported-privilege&gt; 
        &lt;/D:supported-privilege-set&gt; 
        &lt;D:current-user-privilege-set&gt; 
          &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
          &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt; 
        &lt;/D:current-user-privilege-set&gt; 
        &lt;D:acl&gt; 
          &lt;D:ace&gt; 
            &lt;D:principal&gt; 
              &lt;D:href&gt;http://www.example.com/users/esedlar&lt;/D:href&gt; 
            &lt;/D:principal&gt;  
            &lt;D:grant&gt; 
              &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
              &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt; 
              &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt;
            &lt;/D:grant&gt; 
          &lt;/D:ace&gt; 
          &lt;D:ace&gt; 
            &lt;D:principal&gt; 
              &lt;D:href&gt;http://www.example.com/groups/mrktng&lt;/D:href&gt; 
            &lt;/D:principal&gt; 
            &lt;D:deny&gt; 
              &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;
            &lt;/D:deny&gt; 
          &lt;/D:ace&gt; 
          &lt;D:ace&gt; 
            &lt;D:principal&gt; 
              &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt;
            &lt;/D:principal&gt; 
            &lt;D:grant&gt; 
              &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt; 
              &lt;D:privilege&gt;&lt;D:write-acl/&gt;&lt;/D:privilege&gt;
            &lt;/D:grant&gt; 
          &lt;/D:ace&gt; 
          &lt;D:ace&gt; 
            &lt;D:principal&gt;&lt;D:all/&gt;&lt;/D:principal&gt; 
            &lt;D:grant&gt; 
              &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;
            &lt;/D:grant&gt; 
            &lt;D:inherited&gt; 
              &lt;D:href&gt;http://www.example.com/top&lt;/D:href&gt; 
            &lt;/D:inherited&gt; 
          &lt;/D:ace&gt;
        &lt;/D:acl&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt;
  &lt;/D:response&gt;
&lt;/D:multistatus&gt; 
</pre></div><div id="rfc.section.5.9.p.2"><p>The value of the DAV:owner property is a single DAV:href XML element containing the URL of the principal that owns this resource.<a class="self" href="#rfc.section.5.9.p.2">&para;</a></p></div><div id="rfc.section.5.9.p.3" class="avoidbreakafter"><p>The value of the DAV:supported-privilege-set property is a tree of supported privileges (using "[XML Namespace , localname]" to identify each privilege):<a class="self" href="#rfc.section.5.9.p.3">&para;</a></p></div><div id="rfc.figure.u.61"><pre class="drawing">[DAV:, all] (aggregate, abstract) 
   &#9474;
   &#9500;&#9472;&#9472; [DAV:, read] 
   &#9492;&#9472;&#9472; [DAV:, write] (aggregate, abstract) 
          &#9474;
          &#9500;&#9472;&#9472; [http://www.example.com/acl, create] 
          &#9500;&#9472;&#9472; [http://www.example.com/acl, update] 
          &#9492;&#9472;&#9472; [http://www.example.com/acl, delete] 
   &#9500;&#9472;&#9472; [DAV:, read-acl] 
   &#9492;&#9472;&#9472; [DAV:, write-acl] 
</pre></div><div id="rfc.section.5.9.p.4" class="avoidbreakafter"><p>The DAV:current-user-privilege-set property contains two privileges, DAV:read, and DAV:read-acl. This indicates that the current authenticated user only has the ability to read the resource, and read the DAV:acl property on the resource. The DAV:acl property contains a set of four ACEs:<a class="self" href="#rfc.section.5.9.p.4">&para;</a></p></div><div id="rfc.section.5.9.p.5"><p>ACE #1: The principal identified by the URL http://www.example.com/users/esedlar is granted the DAV:read, DAV:write, and DAV:read-acl privileges.<a class="self" href="#rfc.section.5.9.p.5">&para;</a></p></div><div id="rfc.section.5.9.p.6"><p>ACE #2: The principals identified by the URL http://www.example.com/groups/mrktng are denied the DAV:read privilege. In this example, the principal URL identifies a group.<a class="self" href="#rfc.section.5.9.p.6">&para;</a></p></div><div id="rfc.section.5.9.p.7"><p>ACE #3: In this ACE, the principal is a property principal, specifically the DAV:owner property. When evaluating this ACE, the value of the DAV:owner property is retrieved, and is examined to see if it contains a DAV:href XML element. If so, the URL within the DAV:href element is read, and identifies a principal. In this ACE, the owner is granted DAV:read-acl, and DAV:write-acl privileges.<a class="self" href="#rfc.section.5.9.p.7">&para;</a></p></div><div id="rfc.section.5.9.p.8"><p>ACE #4: This ACE grants the DAV:all principal (all users) the DAV:read privilege. This ACE is inherited from the resource http://www.example.com/top, the parent collection of this resource.<a class="self" href="#rfc.section.5.9.p.8">&para;</a></p></div></section></section><section id="acl.evaluation"><h2 id="rfc.section.6"><a href="#rfc.section.6">6.</a>&nbsp;<a href="#acl.evaluation">ACL Evaluation</a></h2><div id="rfc.section.6.p.1"><p>WebDAV ACLs are evaluated in similar manner as ACLs on Windows NT and in NFSv4 <a href="#RFC3530" id="rfc.xref.RFC3530.1"><cite title="Network File System (NFS) version 4 Protocol">[RFC3530]</cite></a>). An ACL is evaluated to determine whether or not access will be granted for a WebDAV request. ACEs are maintained in a particular order, and are evaluated until all of the permissions required by the current request have been granted, at which point the ACL evaluation is terminated and access is granted. If, during ACL evaluation, a &lt;deny&gt; ACE (matching the current user) is encountered for a privilege which has not yet been granted, the ACL evaluation is terminated and access is denied. Failure to have all required privileges granted results in access being denied.<a class="self" href="#rfc.section.6.p.1">&para;</a></p></div><div id="rfc.section.6.p.2" class="avoidbreakafter"><p>Note that the semantics of many other existing ACL systems may be represented via this mechanism, by mixing deny and grant ACEs. For example, consider the standard "rwx" privilege scheme used by UNIX. In this scheme, if the current user is the owner of the file, access is granted if the corresponding privilege bit is set and denied if not set, regardless of the permissions set on the file's group and for the world. An ACL for UNIX permissions of "r--rw-r--" might be constructed like:<a class="self" href="#rfc.section.6.p.2">&para;</a></p></div><div id="rfc.figure.u.62"><pre class="drawing">&lt;D:acl&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;
      &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt;
    &lt;/D:principal&gt; 
    &lt;D:grant&gt;
      &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;
      &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt;
    &lt;/D:principal&gt; 
    &lt;D:deny&gt;
      &lt;D:privilege&gt;&lt;D:all/&gt;&lt;/D:privilege&gt;
    &lt;/D:deny&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;
      &lt;D:property&gt;&lt;D:group/&gt;&lt;/D:property&gt;
    &lt;/D:principal&gt; 
    &lt;D:grant&gt;
      &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
      &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt;
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;
      &lt;D:property&gt;&lt;D:group/&gt;&lt;/D:property&gt;
    &lt;/D:principal&gt; 
    &lt;D:deny&gt;
      &lt;D:privilege&gt;&lt;D:all/&gt;&lt;/D:privilege&gt;
    &lt;/D:deny&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;&lt;D:all&gt;&lt;/D:principal&gt; 
    &lt;D:grant&gt;
      &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt;
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
&lt;/D:acl&gt; 
</pre></div><div id="rfc.section.6.p.3" class="avoidbreakafter"><p>and the &lt;acl-restrictions&gt; would be defined as:<a class="self" href="#rfc.section.6.p.3">&para;</a></p></div><div id="rfc.figure.u.63"><pre class="text">&lt;D:no-invert/&gt;
&lt;D:required-principal&gt; 
  &lt;D:all/&gt; 
  &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt; 
  &lt;D:property&gt;&lt;D:group/&gt;&lt;D:group/&gt; 
&lt;/D:required-principal&gt; 
</pre></div><div id="rfc.section.6.p.4"><p>Note that the client can still get errors from a UNIX server in spite of obeying the &lt;acl-restrictions&gt;, including &lt;D:allowed-principal&gt; (adding an ACE specifying a principal other than the ones in the ACL above) or &lt;D:ace-conflict&gt; (by trying to reorder the ACEs in the example above), as these particular implementation semantics are too complex to be captured with the simple (but general) declarative restrictions.<a class="self" href="#rfc.section.6.p.4">&para;</a></p></div></section><section id="access.control.and.existing.methods"><h2 id="rfc.section.7"><a href="#rfc.section.7">7.</a>&nbsp;<a href="#access.control.and.existing.methods">Access Control and existing methods</a></h2><div id="rfc.section.7.p.1"><p>This section defines the impact of access control functionality on existing methods.<a class="self" href="#rfc.section.7.p.1">&para;</a></p></div><section id="n-any-http-method"><h3 id="rfc.section.7.1"><a href="#rfc.section.7.1">7.1.</a>&nbsp;<a href="#n-any-http-method">Any HTTP method</a></h3><section id="n-error-handling"><h4 id="rfc.section.7.1.1"><a href="#rfc.section.7.1.1">7.1.1.</a>&nbsp;<a href="#n-error-handling">Error Handling</a></h4><div id="rfc.section.7.1.1.p.1" class="avoidbreakafter"><p>The WebDAV ACL mechanism requires the usage of HTTP method "preconditions" as described in section <a href="https://tools.ietf.org/html/rfc3253#section-1.6" id="rfc.xref.RFC3253.4">1.6</a> of RFC3253 for ALL HTTP methods. All HTTP methods have an additional precondition called DAV:need-privileges. If an HTTP method fails due to insufficient privileges, the response body to the "403 Forbidden" error <em class="bcp14">MUST</em> contain the &lt;DAV:error&gt; element, which in turn contains the &lt;DAV:need-privileges&gt; element, which contains one or more &lt;DAV:resource&gt; elements indicating which resource had insufficient privileges, and what the lacking privileges were:<a class="self" href="#rfc.section.7.1.1.p.1">&para;</a></p></div><div id="rfc.figure.u.64"><pre class="inline">&lt;!ELEMENT need-privileges (resource)* &gt; 
&lt;!ELEMENT resource ( href , privilege ) &gt; 
</pre></div><div id="rfc.section.7.1.1.p.2" class="avoidbreakafter"><p>Since some methods require multiple permissions on multiple resources, this information is needed to resolve any ambiguity. There is no requirement that all privilege violations be reported - for implementation reasons, some servers may only report the first privilege violation. For example:<a class="self" href="#rfc.section.7.1.1.p.2">&para;</a></p></div><div id="rfc.figure.u.65"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">MOVE /a/b/ HTTP/1.1 
Host: www.example.com 
Destination: http://www.example.com/c/d 
</pre></div><div id="rfc.figure.u.66"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 403 Forbidden 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;D:error xmlns:D="DAV:"&gt; 
  &lt;D:need-privileges&gt; 
    &lt;D:resource&gt; 
      &lt;D:href&gt;/a&lt;/D:href&gt; 
      &lt;D:privilege&gt;&lt;D:unbind/&gt;&lt;/D:privilege&gt; 
    &lt;/D:resource&gt; 
    &lt;D:resource&gt; 
      &lt;D:href&gt;/c&lt;/D:href&gt; 
      &lt;D:privilege&gt;&lt;D:bind/&gt;&lt;/D:privilege&gt; 
    &lt;/D:resource&gt; 
  &lt;/D:need-privileges&gt; 
&lt;/D:error&gt; 
</pre></div></section></section><section id="METHOD_options"><h3 id="rfc.section.7.2"><a href="#rfc.section.7.2">7.2.</a>&nbsp;<a href="#METHOD_options">OPTIONS</a></h3><div id="rfc.section.7.2.p.1"><p>If the server supports access control, it <em class="bcp14">MUST</em> return "access-control" as a field in the DAV response header from an OPTIONS request on any resource implemented by that server. A value of "access-control" in the DAV header <em class="bcp14">MUST</em> indicate that the server supports all <em class="bcp14">MUST</em> level requirements and <em class="bcp14">REQUIRED</em> features specified in this document.<a class="self" href="#rfc.section.7.2.p.1">&para;</a></p></div><section id="n-example---options"><h4 id="rfc.section.7.2.1"><a href="#rfc.section.7.2.1">7.2.1.</a>&nbsp;<a href="#n-example---options">Example - OPTIONS</a></h4><div id="rfc.figure.u.67"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">OPTIONS /foo.html HTTP/1.1  
Host: www.example.com 
Content-Length: 0 
</pre></div><div id="rfc.figure.u.68"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 200 OK 
DAV: 1, 2, access-control 
Allow: OPTIONS, GET, PUT, PROPFIND, PROPPATCH, ACL 
</pre></div><div id="rfc.section.7.2.1.p.1"><p>In this example, the OPTIONS response indicates that the server supports access control and that /foo.html can have its access control list modified by the ACL method.<a class="self" href="#rfc.section.7.2.1.p.1">&para;</a></p></div></section></section><section id="n-move"><h3 id="rfc.section.7.3"><a href="#rfc.section.7.3">7.3.</a>&nbsp;<a href="#n-move">MOVE</a></h3><div id="rfc.section.7.3.p.1"><p>When a resource is moved from one location to another due to a MOVE request, the non-inherited and non-protected ACEs in the DAV:acl property of the resource <em class="bcp14">MUST NOT</em> be modified, or the MOVE request fails. Handling of inherited and protected ACEs is intentionally undefined to give server implementations flexibility in how they implement ACE inheritance and protection.<a class="self" href="#rfc.section.7.3.p.1">&para;</a></p></div></section><section id="n-copy"><h3 id="rfc.section.7.4"><a href="#rfc.section.7.4">7.4.</a>&nbsp;<a href="#n-copy">COPY</a></h3><div id="rfc.section.7.4.p.1"><p>The DAV:acl property on the resource at the destination of a COPY <em class="bcp14">MUST</em> be the same as if the resource was created by an individual resource creation request (e.g., MKCOL, PUT). Clients wishing to preserve the DAV:acl property across a copy need to read the DAV:acl property prior to the COPY, then perform an ACL operation on the new resource at the destination to restore, insofar as this is possible, the original access control list.<a class="self" href="#rfc.section.7.4.p.1">&para;</a></p></div></section><section id="n-lock"><h3 id="rfc.section.7.5"><a href="#rfc.section.7.5">7.5.</a>&nbsp;<a href="#n-lock">LOCK</a></h3><div id="rfc.section.7.5.p.1"><p>A lock on a resource ensures that only the lock owner can modify ACEs that are not inherited and not protected (these are the only ACEs that a client can modify with an ACL request). A lock does not protect inherited or protected ACEs, since a client cannot modify them with an ACL request on that resource.<a class="self" href="#rfc.section.7.5.p.1">&para;</a></p></div></section></section><section id="access.control.methods"><h2 id="rfc.section.8"><a href="#rfc.section.8">8.</a>&nbsp;<a href="#access.control.methods">Access Control Methods</a></h2><section id="METHOD_ACL"><h3 id="rfc.section.8.1"><a href="#rfc.section.8.1">8.1.</a>&nbsp;<a href="#METHOD_ACL">ACL</a></h3><div id="rfc.section.8.1.p.1"><p>The ACL method modifies the access control list (which can be read via the DAV:acl property) of a resource. Specifically, the ACL method only permits modification to ACEs that are not inherited, and are not protected. An ACL method invocation modifies all non-inherited and non-protected ACEs in a resource's access control list to exactly match the ACEs contained within in the DAV:acl XML element (specified in <a href="#PROPERTY_acl" title="DAV:acl">Section&nbsp;5.5</a>) of the request body. An ACL request body <em class="bcp14">MUST</em> contain only one DAV:acl XML element. Unless the non-inherited and non-protected ACEs of the DAV:acl property of the resource can be updated to be exactly the value specified in the ACL request, the ACL request <em class="bcp14">MUST</em> fail.<a class="self" href="#rfc.section.8.1.p.1">&para;</a></p></div><div id="rfc.section.8.1.p.2"><p>It is possible that the ACEs visible to the current user in the DAV:acl property may only be a portion of the complete set of ACEs on that resource. If this is the case, an ACL request only modifies the set of ACEs visible to the current user, and does not affect any non-visible ACE.<a class="self" href="#rfc.section.8.1.p.2">&para;</a></p></div><div id="rfc.section.8.1.p.3"><p>In order to avoid overwriting DAV:acl changes by another client, a client <em class="bcp14">SHOULD</em> acquire a WebDAV lock on the resource before retrieving the DAV:acl property of a resource that it intends on updating.<a class="self" href="#rfc.section.8.1.p.3">&para;</a></p></div><div id="rfc.section.8.1.p.4"><ul class="empty"><li><b>Implementation Note:</b> Two common operations are to add or remove an ACE from an existing access control list. To accomplish this, a client uses the PROPFIND method to retrieve the value of the DAV:acl property, then parses the returned access control list to remove all inherited and protected ACEs (these ACEs are tagged with the DAV:inherited and DAV:protected XML elements). In the remaining set of non-inherited, non-protected ACEs, the client can add or remove one or more ACEs before submitting the final ACE set in the request body of the ACL method.</li></ul></div><section id="acl.preconditions"><h4 id="rfc.section.8.1.1"><a href="#rfc.section.8.1.1">8.1.1.</a>&nbsp;<a href="#acl.preconditions">ACL Preconditions</a></h4><div id="rfc.section.8.1.1.p.1"><p>An implementation <em class="bcp14">MUST</em> enforce the following constraints on an ACL request. If the constraint is violated, a 403 (Forbidden) or 409 (Conflict) response <em class="bcp14">MUST</em> be returned and the indicated XML element <em class="bcp14">MUST</em> be returned as a child of a top level DAV:error element in an XML response body.<a class="self" href="#rfc.section.8.1.1.p.1">&para;</a></p></div><div id="rfc.section.8.1.1.p.2"><p>Though these status elements are generally expressed as empty XML elements (and are defined as EMPTY in the DTD), implementations <em class="bcp14">MAY</em> return additional descriptive XML elements as children of the status element. Clients <em class="bcp14">MUST</em> be able to accept children of these status elements. Clients that do not understand the additional XML elements should ignore them.<a class="self" href="#rfc.section.8.1.1.p.2">&para;</a></p></div><div id="rfc.section.8.1.1.p.3"><p><span id="rfc.iref.d.2"></span> <span id="rfc.iref.c.1"></span> (DAV:no-ace-conflict): The ACEs submitted in the ACL request <em class="bcp14">MUST NOT</em> conflict with each other. This is a catchall error code indicating that an implementation-specific ACL restriction has been violated.<a class="self" href="#rfc.section.8.1.1.p.3">&para;</a></p></div><div id="rfc.section.8.1.1.p.4"><p><span id="rfc.iref.d.3"></span> <span id="rfc.iref.c.2"></span> (DAV:no-protected-ace-conflict): The ACEs submitted in the ACL request <em class="bcp14">MUST NOT</em> conflict with the protected ACEs on the resource. For example, if the resource has a protected ACE granting DAV:write to a given principal, then it would not be consistent if the ACL request submitted an ACE denying DAV:write to the same principal.<a class="self" href="#rfc.section.8.1.1.p.4">&para;</a></p></div><div id="rfc.section.8.1.1.p.5"><p><span id="rfc.iref.d.4"></span> <span id="rfc.iref.c.3"></span> (DAV:no-inherited-ace-conflict): The ACEs submitted in the ACL request <em class="bcp14">MUST NOT</em> conflict with the inherited ACEs on the resource. For example, if the resource inherits an ACE from its parent collection granting DAV:write to a given principal, then it would not be consistent if the ACL request submitted an ACE denying DAV:write to the same principal. Note that reporting of this error will be implementation-dependent. Implementations <em class="bcp14">MUST</em> either report this error or allow the ACE to be set, and then let normal ACE evaluation rules determine whether the new ACE has any impact on the privileges available to a specific principal.<a class="self" href="#rfc.section.8.1.1.p.5">&para;</a></p></div><div id="rfc.section.8.1.1.p.6"><p><span id="rfc.iref.d.5"></span> <span id="rfc.iref.c.4"></span> (DAV:limited-number-of-aces): The number of ACEs submitted in the ACL request <em class="bcp14">MUST NOT</em> exceed the number of ACEs allowed on that resource. However, ACL-compliant servers <em class="bcp14">MUST</em> support at least one ACE granting privileges to a single principal, and one ACE granting privileges to a group.<a class="self" href="#rfc.section.8.1.1.p.6">&para;</a></p></div><div id="rfc.section.8.1.1.p.7"><p><span id="rfc.iref.d.6"></span> <span id="rfc.iref.c.5"></span> (DAV:deny-before-grant): All non-inherited deny ACEs <em class="bcp14">MUST</em> precede all non-inherited grant ACEs.<a class="self" href="#rfc.section.8.1.1.p.7">&para;</a></p></div><div id="rfc.section.8.1.1.p.8"><p><span id="rfc.iref.d.7"></span> <span id="rfc.iref.c.6"></span> (DAV:grant-only): The ACEs submitted in the ACL request <em class="bcp14">MUST NOT</em> include a deny ACE. This precondition applies only when the ACL restrictions of the resource include the DAV:grant-only constraint (defined in <a href="#RESTRICTIONS_grant-only" title="DAV:grant-only">Section&nbsp;5.6.1</a>).<a class="self" href="#rfc.section.8.1.1.p.8">&para;</a></p></div><div id="rfc.section.8.1.1.p.9"><p><span id="rfc.iref.d.8"></span> <span id="rfc.iref.c.7"></span> (DAV:no-invert): The ACL request <em class="bcp14">MUST NOT</em> include a DAV:invert element. This precondition applies only when the ACL semantics of the resource includes the DAV:no-invert constraint (defined in <a href="#CONSTRAINT_no-invert" title="DAV:no-invert ACE Constraint">Section&nbsp;5.6.2</a>).<a class="self" href="#rfc.section.8.1.1.p.9">&para;</a></p></div><div id="rfc.section.8.1.1.p.10"><p><span id="rfc.iref.d.9"></span> <span id="rfc.iref.c.8"></span> (DAV:no-abstract): The ACL request <em class="bcp14">MUST NOT</em> attempt to grant or deny an abstract privilege (see <a href="#PROPERTY_supported-privilege-set" title="DAV:supported-privilege-set">Section&nbsp;5.3</a>).<a class="self" href="#rfc.section.8.1.1.p.10">&para;</a></p></div><div id="rfc.section.8.1.1.p.11"><p><span id="rfc.iref.d.10"></span> <span id="rfc.iref.c.9"></span> (DAV:not-supported-privilege): The ACEs submitted in the ACL request <em class="bcp14">MUST</em> be supported by the resource.<a class="self" href="#rfc.section.8.1.1.p.11">&para;</a></p></div><div id="rfc.section.8.1.1.p.12"><p><span id="rfc.iref.d.11"></span> <span id="rfc.iref.c.10"></span> (DAV:missing-required-principal): The result of the ACL request <em class="bcp14">MUST</em> have at least one ACE for each principal identified in a DAV:required-principal XML element in the ACL semantics of that resource (see <a href="#PROPERTY_acl" title="DAV:acl">Section&nbsp;5.5</a>).<a class="self" href="#rfc.section.8.1.1.p.12">&para;</a></p></div><div id="rfc.section.8.1.1.p.13"><p><span id="rfc.iref.d.12"></span> <span id="rfc.iref.c.11"></span> (DAV:recognized-principal): Every principal URL in the ACL request <em class="bcp14">MUST</em> identify a principal resource.<a class="self" href="#rfc.section.8.1.1.p.13">&para;</a></p></div><div id="rfc.section.8.1.1.p.14"><p><span id="rfc.iref.d.13"></span> <span id="rfc.iref.c.12"></span> (DAV:allowed-principal): The principals specified in the ACEs submitted in the ACL request <em class="bcp14">MUST</em> be allowed as principals for the resource. For example, a server where only authenticated principals can access resources would not allow the DAV:all or DAV:unauthenticated principals to be used in an ACE, since these would allow unauthenticated access to resources.<a class="self" href="#rfc.section.8.1.1.p.14">&para;</a></p></div></section><section id="n-example--the-acl-method"><h4 id="rfc.section.8.1.2"><a href="#rfc.section.8.1.2">8.1.2.</a>&nbsp;<a href="#n-example--the-acl-method">Example: the ACL method</a></h4><div id="rfc.section.8.1.2.p.1"><p>In the following example, user "fielding", authenticated by information in the Authorization header, grants the principal identified by the URL http://www.example.com/users/esedlar (i.e., the user "esedlar") read and write privileges, grants the owner of the resource read-acl and write-acl privileges, and grants everyone read privileges.<a class="self" href="#rfc.section.8.1.2.p.1">&para;</a></p></div><div id="rfc.figure.u.69"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">ACL /top/container/ HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Authorization: Digest username="fielding",  
  realm="users@example.com", nonce="...", 
  uri="/top/container/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:acl xmlns:D="DAV:"&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt; 
      &lt;D:href&gt;http://www.example.com/users/esedlar&lt;/D:href&gt; 
    &lt;/D:principal&gt; 
    &lt;D:grant&gt; 
      &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
      &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt;  
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt; 
      &lt;D:property&gt;&lt;D:owner/&gt;&lt;/D:property&gt;  
    &lt;/D:principal&gt; 
    &lt;D:grant&gt; 
      &lt;D:privilege&gt;&lt;D:read-acl/&gt;&lt;/D:privilege&gt; 
      &lt;D:privilege&gt;&lt;D:write-acl/&gt;&lt;/D:privilege&gt;  
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt;&lt;D:all/&gt;&lt;/D:principal&gt; 
    &lt;D:grant&gt; 
      &lt;D:privilege&gt;&lt;D:read/&gt;&lt;/D:privilege&gt; 
    &lt;/D:grant&gt; 
  &lt;/D:ace&gt;
&lt;/D:acl&gt; 
</pre></div><div id="rfc.figure.u.70"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 200 OK 
</pre></div></section><section id="n-example--acl-method-failure-due-to-protected-ace-conflict"><h4 id="rfc.section.8.1.3"><a href="#rfc.section.8.1.3">8.1.3.</a>&nbsp;<a href="#n-example--acl-method-failure-due-to-protected-ace-conflict">Example: ACL method failure due to protected ACE conflict</a></h4><div id="rfc.section.8.1.3.p.1"><p>In the following request, user "fielding", authenticated by information in the Authorization header, attempts to deny the principal identified by the URL http://www.example.com/users/esedlar (i.e., the user "esedlar") write privileges. Prior to the request, the DAV:acl property on the resource contained a protected ACE (see <a href="#ace.protection" title="ACE Protection">Section&nbsp;5.5.3</a>) granting DAV:owner the DAV:read and DAV:write privileges. The principal identified by URL http://www.example.com/users/esedlar is the owner of the resource. The ACL method invocation fails because the submitted ACE conflicts with the protected ACE, thus violating the semantics of ACE protection.<a class="self" href="#rfc.section.8.1.3.p.1">&para;</a></p></div><div id="rfc.figure.u.71"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">ACL /top/container/ HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Authorization: Digest username="fielding",  
  realm="users@example.com", nonce="...", 
  uri="/top/container/", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:acl xmlns:D="DAV:"&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt; 
      &lt;D:href&gt;http://www.example.com/users/esedlar&lt;/D:href&gt; 
    &lt;/D:principal&gt; 
    &lt;D:deny&gt;  
      &lt;D:privilege&gt;&lt;D:write/&gt;&lt;/D:privilege&gt;  
    &lt;/D:deny&gt; 
  &lt;/D:ace&gt; 
&lt;/D:acl&gt; 
</pre></div><div id="rfc.figure.u.72"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 403 Forbidden 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:error xmlns:D="DAV:"&gt; 
  &lt;D:no-protected-ace-conflict/&gt; 
&lt;/D:error&gt; 
</pre></div></section><section id="n-example--acl-method-failure-due-to-an-inherited-ace-conflict"><h4 id="rfc.section.8.1.4"><a href="#rfc.section.8.1.4">8.1.4.</a>&nbsp;<a href="#n-example--acl-method-failure-due-to-an-inherited-ace-conflict">Example: ACL method failure due to an inherited ACE conflict</a></h4><div id="rfc.section.8.1.4.p.1"><p>In the following request, user "ejw", authenticated by information in the Authorization header, tries to change the access control list on the resource http://www.example.com/top/index.html. This resource has two inherited ACEs.<a class="self" href="#rfc.section.8.1.4.p.1">&para;</a></p></div><div id="rfc.section.8.1.4.p.2"><p>Inherited ACE #1 grants the principal identified by URL http://www.example.com/users/ejw (i.e., the user "ejw") http://www.example.com/privs/write-all and DAV:read-acl privileges. On this server, http://www.example.com/privs/write-all is an aggregate privilege containing DAV:write, and DAV:write-acl.<a class="self" href="#rfc.section.8.1.4.p.2">&para;</a></p></div><div id="rfc.section.8.1.4.p.3"><p>Inherited ACE #2 grants principal DAV:all the DAV:read privilege.<a class="self" href="#rfc.section.8.1.4.p.3">&para;</a></p></div><div id="rfc.section.8.1.4.p.4"><p>The request attempts to set a (non-inherited) ACE, denying the principal identified by the URL http://www.example.com/users/ejw (i.e., the user "ejw") DAV:write permission. This conflicts with inherited ACE #1. Note that the decision to report an inherited ACE conflict is specific to this server implementation. Another server implementation could have allowed the new ACE to be set, and then used normal ACE evaluation rules to determine whether the new ACE has any impact on the privileges available to a principal.<a class="self" href="#rfc.section.8.1.4.p.4">&para;</a></p></div><div id="rfc.figure.u.73"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">ACL /top/index.html HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Authorization: Digest username="ejw",  
  realm="users@example.com", nonce="...", 
  uri="/top/index.html", response="...", opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:acl xmlns:D="DAV:" xmlns:F="http://www.example.com/privs/"&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt; 
       &lt;D:href&gt;http://www.example.com/users/ejw&lt;/D:href&gt; 
    &lt;/D:principal&gt; 
    &lt;D:grant&gt;&lt;D:write/&gt;&lt;/D:grant&gt; 
  &lt;/D:ace&gt; 
&lt;/D:acl&gt; 
</pre></div><div id="rfc.figure.u.74"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 403 Forbidden 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:error xmlns:D="DAV:"&gt; 
  &lt;D:no-inherited-ace-conflict/&gt; 
&lt;/D:error&gt; 
</pre></div></section><section id="n-example--acl-method-failure-due-to-an-attempt-to-set-grant-and-deny-in-a-single-ace"><h4 id="rfc.section.8.1.5"><a href="#rfc.section.8.1.5">8.1.5.</a>&nbsp;<a href="#n-example--acl-method-failure-due-to-an-attempt-to-set-grant-and-deny-in-a-single-ace">Example: ACL method failure due to an attempt to set grant and deny in a single ACE</a></h4><div id="rfc.section.8.1.5.p.1"><p>In this example, user "ygoland", authenticated by information in the Authorization header, tries to change the access control list on the resource http://www.example.com/diamond/engagement-ring.gif. The ACL request includes a single, syntactically and semantically incorrect ACE, which attempts to grant the group identified by the URL http://www.example.com/users/friends DAV:read privilege and deny the principal identified by URL http://www.example.com/users/ygoland-so (i.e., the user "ygoland-so") DAV:read privilege. However, it is illegal to have multiple principal elements, as well as both a grant and deny element in the same ACE, so the request fails due to poor syntax.<a class="self" href="#rfc.section.8.1.5.p.1">&para;</a></p></div><div id="rfc.figure.u.75"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">ACL /diamond/engagement-ring.gif HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Authorization: Digest username="ygoland",  
  realm="users@example.com", nonce="...", 
  uri="/diamond/engagement-ring.gif", response="...", 
  opaque="..." 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:acl xmlns:D="DAV:"&gt; 
  &lt;D:ace&gt; 
    &lt;D:principal&gt; 
      &lt;D:href&gt;http://www.example.com/users/friends&lt;/D:href&gt; 
    &lt;/D:principal&gt; 
    &lt;D:grant&gt;&lt;D:read/&gt;&lt;/D:grant&gt; 
    &lt;D:principal&gt; 
      &lt;D:href&gt;http://www.example.com/users/ygoland-so&lt;/D:href&gt; 
    &lt;/D:principal&gt; 
    &lt;D:deny&gt;&lt;D:read/&gt;&lt;/D:deny&gt; 
  &lt;/D:ace&gt; 
&lt;/D:acl&gt; 
</pre></div><div id="rfc.figure.u.76"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 400 Bad Request 
Content-Length: 0 
</pre></div><div id="rfc.section.8.1.5.p.2"><p>Note that if the request had been divided into two ACEs, one to grant, and one to deny, the request would have been syntactically well formed.<a class="self" href="#rfc.section.8.1.5.p.2">&para;</a></p></div></section></section></section><section id="access.control.reports"><h2 id="rfc.section.9"><a href="#rfc.section.9">9.</a>&nbsp;<a href="#access.control.reports">Access Control Reports</a></h2><section id="n-report-method"><h3 id="rfc.section.9.1"><a href="#rfc.section.9.1">9.1.</a>&nbsp;<a href="#n-report-method">REPORT Method</a></h3><div id="rfc.section.9.1.p.1"><p>The REPORT method (defined in <a href="https://tools.ietf.org/html/rfc3253#section-3.6">Section 3.6</a> of <a href="#RFC3253" id="rfc.xref.RFC3253.5"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>) provides an extensible mechanism for obtaining information about a resource. Unlike the PROPFIND method, which returns the value of one or more named properties, the REPORT method can involve more complex processing. REPORT is valuable in cases where the server has access to all of the information needed to perform the complex request (such as a query), and where it would require multiple requests for the client to retrieve the information needed to perform the same request.<a class="self" href="#rfc.section.9.1.p.1">&para;</a></p></div><div id="rfc.section.9.1.p.2"><p>A server that supports the WebDAV Access Control Protocol <em class="bcp14">MUST</em> support the DAV:expand-property report (defined in <a href="https://tools.ietf.org/html/rfc3253#section-3.8">Section 3.8</a> of <a href="#RFC3253" id="rfc.xref.RFC3253.6"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>).<a class="self" href="#rfc.section.9.1.p.2">&para;</a></p></div></section><section id="REPORT_acl-principal-prop-set"><h3 id="rfc.section.9.2"><a href="#rfc.section.9.2">9.2.</a>&nbsp;<a href="#REPORT_acl-principal-prop-set">DAV:acl-principal-prop-set Report</a></h3><div id="rfc.section.9.2.p.1"><p>The DAV:acl-principal-prop-set report returns, for all principals in the DAV:acl property (of the Request-URI) that are identified by http(s) URLs or by a DAV:property principal, the value of the properties specified in the REPORT request body. In the case where a principal URL appears multiple times, the DAV:acl-principal-prop-set report <em class="bcp14">MUST</em> return the properties for that principal only once. Support for this report is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.9.2.p.1">&para;</a></p></div><div id="rfc.section.9.2.p.2"><p>One expected use of this report is to retrieve the human readable name (found in the DAV:displayname property) of each principal found in an ACL. This is useful for constructing user interfaces that show each ACE in a human readable form.<a class="self" href="#rfc.section.9.2.p.2">&para;</a></p></div><div id="rfc.section.9.2.p.3"><p><b>Marshalling</b> <a class="self" href="#rfc.section.9.2.p.3">&para;</a></p><ul class="empty"><li>The request body <em class="bcp14">MUST</em> be a DAV:acl-principal-prop-set XML element. <span id="rfc.figure.u.77"><pre class="inline">   &lt;!ELEMENT acl-principal-prop-set ANY&gt; 
   ANY value: a sequence of one or more elements, with at most one
              DAV:prop element. 
   prop: see RFC 2518, Section 12.11 
</pre></span> </li><li>This report is only defined when the Depth header has value "0"; other values result in a 400 (Bad Request) error response. Note that <a href="#RFC3253" id="rfc.xref.RFC3253.7"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>, <a href="https://tools.ietf.org/html/rfc3253#section-3.6">Section 3.6</a>, states that if the Depth header is not present, it defaults to a value of "0".</li><li>The response body for a successful request <em class="bcp14">MUST</em> be a DAV:multistatus XML element (i.e., the response uses the same format as the response for PROPFIND). In the case where there are no response elements, the returned multistatus XML element is empty. <span id="rfc.figure.u.78"><pre class="inline">   multistatus: see RFC 2518, Section 12.9 
</pre></span> </li><li>The response body for a successful DAV:acl-principal-prop-set REPORT request <em class="bcp14">MUST</em> contain a DAV:response element for each principal identified by an http(s) URL listed in a DAV:principal XML element of an ACE within the DAV:acl property of the resource identified by the Request-URI.</li></ul></div><div id="rfc.section.9.2.p.4"><p><b>Postconditions:</b> <a class="self" href="#rfc.section.9.2.p.4">&para;</a></p><ul class="empty"><li><span id="rfc.iref.d.14"></span> <span id="rfc.iref.c.13"></span> (DAV:number-of-matches-within-limits): The number of matching principals must fall within server-specific, predefined limits. For example, this condition might be triggered if a search specification would cause the return of an extremely large number of responses.</li></ul></div><section id="n-example--dav-acl-principal-prop-set-report"><h4 id="rfc.section.9.2.1"><a href="#rfc.section.9.2.1">9.2.1.</a>&nbsp;<a href="#n-example--dav-acl-principal-prop-set-report">Example: DAV:acl-principal-prop-set Report</a></h4><div id="rfc.section.9.2.1.p.1" class="avoidbreakafter"><p>Resource http://www.example.com/index.html has an ACL with three ACEs:<a class="self" href="#rfc.section.9.2.1.p.1">&para;</a></p></div><div id="rfc.section.9.2.1.p.2"><p>ACE #1: All principals (DAV:all) have DAV:read and DAV:read-current-user-privilege-set access.<a class="self" href="#rfc.section.9.2.1.p.2">&para;</a></p></div><div id="rfc.section.9.2.1.p.3"><p>ACE #2: The principal identified by http://www.example.com/people/gstein (the user "gstein") is granted DAV:write, DAV:write-acl, DAV:read-acl privileges.<a class="self" href="#rfc.section.9.2.1.p.3">&para;</a></p></div><div id="rfc.section.9.2.1.p.4"><p>ACE #3: The group identified by http://www.example.com/groups/authors (the "authors" group) is granted DAV:write and DAV:read-acl privileges.<a class="self" href="#rfc.section.9.2.1.p.4">&para;</a></p></div><div id="rfc.section.9.2.1.p.5"><p>The following example shows a DAV:acl-principal-prop-set report requesting the DAV:displayname property. It returns the value of DAV:displayname for resources http://www.example.com/people/gstein and http://www.example.com/groups/authors , but not for DAV:all, since this is not an http(s) URL.<a class="self" href="#rfc.section.9.2.1.p.5">&para;</a></p></div><div id="rfc.figure.u.79"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">REPORT /index.html HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Depth: 0  

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:acl-principal-prop-set xmlns:D="DAV:"&gt; 
  &lt;D:prop&gt; 
    &lt;D:displayname/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:acl-principal-prop-set&gt; 
</pre></div><div id="rfc.figure.u.80"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/people/gstein&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:displayname&gt;Greg Stein&lt;/D:displayname&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/groups/authors&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:displayname&gt;Site authors&lt;/D:displayname&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt;  
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="REPORT_principal-match"><h3 id="rfc.section.9.3"><a href="#rfc.section.9.3">9.3.</a>&nbsp;<a href="#REPORT_principal-match">DAV:principal-match REPORT</a></h3><div id="rfc.section.9.3.p.1"><p>The DAV:principal-match REPORT is used to identify all members (at any depth) of the collection identified by the Request-URI that are principals and that match the current user. In particular, if the collection contains principals, the report can be used to identify all members of the collection that match the current user. Alternatively, if the collection contains resources that have a property that identifies a principal (e.g., DAV:owner), the report can be used to identify all members of the collection whose property identifies a principal that matches the current user. For example, this report can return all of the resources in a collection hierarchy that are owned by the current user. Support for this report is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.9.3.p.1">&para;</a></p></div><div id="rfc.section.9.3.p.2"><p><b>Marshalling:</b> <a class="self" href="#rfc.section.9.3.p.2">&para;</a></p><ul class="empty"><li>The request body <em class="bcp14">MUST</em> be a DAV:principal-match XML element. <span id="rfc.figure.u.81"><pre class="inline">   &lt;!ELEMENT principal-match ((principal-property | self), prop?)&gt; 
   &lt;!ELEMENT principal-property ANY&gt; 
   ANY value: an element whose value identifies a property.  The 
   expectation is the value of the named property typically contains 
   an href element that contains the URI of a principal 
   &lt;!ELEMENT self EMPTY&gt; 
   prop: see RFC 2518, Section 12.11
</pre></span> </li><li>This report is only defined when the Depth header has value "0"; other values result in a 400 (Bad Request) error response. Note that <a href="#RFC3253" id="rfc.xref.RFC3253.8"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>, <a href="https://tools.ietf.org/html/rfc3253#section-3.6">Section 3.6</a>, states that if the Depth header is not present, it defaults to a value of "0". The response body for a successful request <em class="bcp14">MUST</em> be a DAV:multistatus XML element. In the case where there are no response elements, the returned multistatus XML element is empty. <span id="rfc.figure.u.82"><pre class="inline">   multistatus: see RFC 2518, Section 12.9 
</pre></span> </li><li>The response body for a successful DAV:principal-match REPORT request <em class="bcp14">MUST</em> contain a DAV:response element for each member of the collection that matches the current user. When the DAV:principal-property element is used, a match occurs if the current user is matched by the principal identified by the URI found in the DAV:href element of the property identified by the DAV:principal-property element. When the DAV:self element is used in a DAV:principal-match report issued against a group, it matches the group if a member identifies the same principal as the current user.</li><li>If DAV:prop is specified in the request body, the properties specified in the DAV:prop element <em class="bcp14">MUST</em> be reported in the DAV:response elements.</li></ul></div><section id="n-example--dav-principal-match-report"><h4 id="rfc.section.9.3.1"><a href="#rfc.section.9.3.1">9.3.1.</a>&nbsp;<a href="#n-example--dav-principal-match-report">Example: DAV:principal-match REPORT</a></h4><div id="rfc.section.9.3.1.p.1"><p>The following example identifies the members of the collection identified by the URL http://www.example.com/doc that are owned by the current user. The current user ("gclemm") is authenticated using Digest authentication.<a class="self" href="#rfc.section.9.3.1.p.1">&para;</a></p></div><div id="rfc.figure.u.83"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">REPORT /doc/ HTTP/1.1 
Host: www.example.com 
Authorization: Digest username="gclemm",  
  realm="users@example.com", nonce="...", 
  uri="/papers/", response="...", opaque="..." 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 
Depth: 0  

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:principal-match xmlns:D="DAV:"&gt; 
  &lt;D:principal-property&gt; 
    &lt;D:owner/&gt; 
  &lt;/D:principal-property&gt; 
&lt;/D:principal-match&gt; 
</pre></div><div id="rfc.figure.u.84"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:"&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/doc/foo.html&lt;/D:href&gt; 
    &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
  &lt;/D:response&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/doc/img/bar.gif&lt;/D:href&gt; 
    &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="REPORT_principal-property-search"><h3 id="rfc.section.9.4"><a href="#rfc.section.9.4">9.4.</a>&nbsp;<a href="#REPORT_principal-property-search">DAV:principal-property-search REPORT</a></h3><div id="rfc.section.9.4.p.1"><p>The DAV:principal-property-search REPORT performs a search for all principals whose properties contain character data that matches the search criteria specified in the request. One expected use of this report is to discover the URL of a principal associated with a given person or group by searching for them by name. This is done by searching over DAV:displayname, which is defined on all principals.<a class="self" href="#rfc.section.9.4.p.1">&para;</a></p></div><div id="rfc.section.9.4.p.2"><p>The actual search method (exact matching vs. substring matching vs, prefix-matching, case-sensitivity) deliberately is left to the server implementation to allow implementation on a wide set of possible user management systems. In cases where the implementation of DAV:principal-property-search is not constrained by the semantics of an underlying user management repository, preferred default semantics are caseless substring matches.<a class="self" href="#rfc.section.9.4.p.2">&para;</a></p></div><div id="rfc.section.9.4.p.3"><p>For implementation efficiency, servers do not typically support searching on all properties. A search requesting properties that are not searchable for a particular principal will not match that principal.<a class="self" href="#rfc.section.9.4.p.3">&para;</a></p></div><div id="rfc.section.9.4.p.4"><p>Support for the DAV:principal-property-search report is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.9.4.p.4">&para;</a></p></div><div id="rfc.section.9.4.p.5"><ul class="empty"><li><b>Implementation Note:</b> The value of a WebDAV property is a sequence of well-formed XML, and hence can include any character in the Unicode/ISO-10646 standard, that is, most known characters in human languages. Due to the idiosyncrasies of case mapping across human languages, implementation of case-insensitive matching is non-trivial. Implementors of servers that do perform substring matching are strongly encouraged to consult "The Unicode Standard" <a href="#UNICODE4" id="rfc.xref.UNICODE4.1"><cite title="The Unicode Standard - Version 4.0">[UNICODE4]</cite></a>, especially Section 5.18, Subsection "Caseless Matching", for guidance when implementing their case-insensitive matching algorithms.</li><li><b>Implementation Note:</b> Some implementations of this protocol will use an LDAP repository for storage of principal metadata. The schema describing each attribute (akin to a WebDAV property) in an LDAP repository specifies whether it supports case-sensitive or caseless searching. One of the benefits of leaving the search method to the discretion of the server implementation is the default LDAP attribute search behavior can be used when implementing the DAV:principal-property-search report.</li></ul></div><div id="rfc.section.9.4.p.6"><p><b>Marshalling:</b> <a class="self" href="#rfc.section.9.4.p.6">&para;</a></p><ul class="empty"><li>The request body <em class="bcp14">MUST</em> be a DAV:principal-property-search XML element containing a search specification and an optional list of properties. For every principal that matches the search specification, the response will contain the value of the requested properties on that principal. <span id="rfc.figure.u.85"><pre class="inline">   &lt;!ELEMENT principal-property-search 
    ((property-search+), prop?, apply-to-principal-collection-set?) &gt; 
</pre></span> </li><li>By default, the report searches all members (at any depth) of the collection identified by the Request-URI. If DAV:apply-to-principal-collection-set is specified in the request body, the request is applied instead to each collection identified by the DAV:principal-collection-set property of the resource identified by the Request-URI.</li><li>The DAV:property-search element contains a prop element enumerating the properties to be searched and a match element, containing the search string. <span id="rfc.figure.u.86"><pre class="inline">   &lt;!ELEMENT property-search (prop, match) &gt; 
   prop: see RFC 2518, Section 12.11 

   &lt;!ELEMENT match #PCDATA &gt; 
</pre></span> </li><li>Multiple property-search elements or multiple elements within a DAV:prop element will be interpreted with a logical AND.</li><li>This report is only defined when the Depth header has value "0"; other values result in a 400 (Bad Request) error response. Note that <a href="#RFC3253" id="rfc.xref.RFC3253.9"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>, <a href="https://tools.ietf.org/html/rfc3253#section-3.6">Section 3.6</a>, states that if the Depth header is not present, it defaults to a value of "0".</li><li>The response body for a successful request <em class="bcp14">MUST</em> be a DAV:multistatus XML element. In the case where there are no response elements, the returned multistatus XML element is empty. <span id="rfc.figure.u.87"><pre class="inline">   multistatus: see RFC 2518, Section 12.9 
</pre></span> </li><li>The response body for a successful DAV:principal-property-search REPORT request <em class="bcp14">MUST</em> contain a DAV:response element for each principal whose property values satisfy the search specification given in DAV:principal-property-search.</li><li>If DAV:prop is specified in the request body, the properties specified in the DAV:prop element <em class="bcp14">MUST</em> be reported in the DAV:response elements.</li></ul></div><div id="rfc.section.9.4.p.7"><p><b>Preconditions:</b> <a class="self" href="#rfc.section.9.4.p.7">&para;</a></p><ul class="empty"><li>None</li></ul></div><div id="rfc.section.9.4.p.8"><p><b>Postconditions:</b> <a class="self" href="#rfc.section.9.4.p.8">&para;</a></p><ul class="empty"><li><span id="rfc.iref.d.15"></span> <span id="rfc.iref.c.14"></span> (DAV:number-of-matches-within-limits): The number of matching principals must fall within server-specific, predefined limits. For example, this condition might be triggered if a search specification would cause the return of an extremely large number of responses.</li></ul></div><section id="n-matching"><h4 id="rfc.section.9.4.1"><a href="#rfc.section.9.4.1">9.4.1.</a>&nbsp;<a href="#n-matching">Matching</a></h4><div id="rfc.section.9.4.1.p.1" class="avoidbreakafter"><p>There are several cases to consider when matching strings. The easiest case is when a property value is "simple" and has only character information item content (see <a href="#REC-XML-INFOSET" id="rfc.xref.REC-XML-INFOSET.1"><cite title="XML Information Set (Second Edition)">[REC-XML-INFOSET]</cite></a>). For example, the search string "julian" would match the DAV:displayname property with value "Julian Reschke". Note that the on-the-wire marshaling of DAV:displayname in this case is:<a class="self" href="#rfc.section.9.4.1.p.1">&para;</a></p></div><div id="rfc.figure.u.88"><pre class="text">&lt;D:displayname xmlns:D="DAV:"&gt;Julian Reschke&lt;/D:displayname&gt; 
</pre></div><div id="rfc.section.9.4.1.p.2"><p>The name of the property is encoded into the XML element information item, and the character information item content of the property is "Julian Reschke".<a class="self" href="#rfc.section.9.4.1.p.2">&para;</a></p></div><div id="rfc.section.9.4.1.p.3" class="avoidbreakafter"><p>A more complicated case occurs when properties have mixed content (that is, compound values consisting of multiple child element items, other types of information items, and character information item content). Consider the property "aprop" in the namespace "http://www.example.com/props/", marshaled as:<a class="self" href="#rfc.section.9.4.1.p.3">&para;</a></p></div><div id="rfc.figure.u.89"><pre class="text">&lt;W:aprop xmlns:W="http://www.example.com/props/"&gt; 
  {cdata 0}&lt;W:elem1&gt;{cdata 1}&lt;/W:elem1&gt; 
  &lt;W:elem2&gt;{cdata 2}&lt;/W:elem2&gt;{cdata 3} 
&lt;/W:aprop&gt; 
</pre></div><div id="rfc.section.9.4.1.p.4" class="avoidbreakafter"><p>In this case, matching is performed on each individual contiguous sequence of character information items. In the example above, a search string would be compared to the four following strings:<a class="self" href="#rfc.section.9.4.1.p.4">&para;</a></p></div><div id="rfc.figure.u.90"><pre class="text">{cdata 0} 
{cdata 1} 
{cdata 2} 
{cdata 3} 
</pre></div><div id="rfc.section.9.4.1.p.5"><p>That is, four individual matches would be performed, one each for {cdata 0}, {cdata 1}, {cdata 2}, and {cdata 3}.<a class="self" href="#rfc.section.9.4.1.p.5">&para;</a></p></div></section><section id="n-example--successful-dav-principal-property-search-report"><h4 id="rfc.section.9.4.2"><a href="#rfc.section.9.4.2">9.4.2.</a>&nbsp;<a href="#n-example--successful-dav-principal-property-search-report">Example: successful DAV:principal-property-search REPORT</a></h4><div id="rfc.section.9.4.2.p.1" class="avoidbreakafter"><p>In this example, the client requests the principal URLs of all users whose DAV:displayname property contains the substring "doE" and whose "title" property in the namespace "http://BigCorp.com/ns/" (that is, their professional title) contains "Sales". In addition, the client requests five properties to be returned with the matching principals:<a class="self" href="#rfc.section.9.4.2.p.1">&para;</a></p></div><div id="rfc.section.9.4.2.p.2"><p>In the DAV: namespace: displayname<a class="self" href="#rfc.section.9.4.2.p.2">&para;</a></p></div><div id="rfc.section.9.4.2.p.3"><p>In the http://www.example.com/ns/ namespace: department, phone, office, salary<a class="self" href="#rfc.section.9.4.2.p.3">&para;</a></p></div><div id="rfc.section.9.4.2.p.4"><p>The response shows that two principal resources meet the search specification, "John Doe" and "Zygdoebert Smith". The property "salary" in namespace "http://www.example.com/ns/" is not returned, since the principal making the request does not have sufficient access permissions to read this property.<a class="self" href="#rfc.section.9.4.2.p.4">&para;</a></p></div><div id="rfc.figure.u.91"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">REPORT /users/ HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset=utf-8 
Content-Length: xxxx 
Depth: 0 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:principal-property-search xmlns:D="DAV:"&gt; 
  &lt;D:property-search&gt; 
    &lt;D:prop&gt; 
      &lt;D:displayname/&gt; 
    &lt;/D:prop&gt; 
    &lt;D:match&gt;doE&lt;/D:match&gt; 
  &lt;/D:property-search&gt; 
  &lt;D:property-search&gt; 
    &lt;D:prop xmlns:B="http://www.example.com/ns/"&gt; 
      &lt;B:title/&gt; 
    &lt;/D:prop&gt; 
    &lt;D:match&gt;Sales&lt;/D:match&gt; 
  &lt;/D:property-search&gt; 
  &lt;D:prop xmlns:B="http://www.example.com/ns/"&gt; 
    &lt;D:displayname/&gt; 
    &lt;B:department/&gt; 
    &lt;B:phone/&gt; 
    &lt;B:office/&gt; 
    &lt;B:salary/&gt; 
  &lt;/D:prop&gt; 
&lt;/D:principal-property-search&gt; 
</pre></div><div id="rfc.figure.u.92"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 207 Multi-Status 
Content-Type: text/xml; charset=utf-8 
Content-Length: xxxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:multistatus xmlns:D="DAV:" xmlns:B="http://BigCorp.com/ns/"&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/users/jdoe&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:displayname&gt;John Doe&lt;/D:displayname&gt; 
        &lt;B:department&gt;Widget Sales&lt;/B:department&gt; 
        &lt;B:phone&gt;234-4567&lt;/B:phone&gt; 
        &lt;B:office&gt;209&lt;/B:office&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;B:salary/&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 403 Forbidden&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
  &lt;D:response&gt; 
    &lt;D:href&gt;http://www.example.com/users/zsmith&lt;/D:href&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;D:displayname&gt;Zygdoebert Smith&lt;/D:displayname&gt; 
        &lt;B:department&gt;Gadget Sales&lt;/B:department&gt; 
        &lt;B:phone&gt;234-7654&lt;/B:phone&gt; 
        &lt;B:office&gt;114&lt;/B:office&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 200 OK&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
    &lt;D:propstat&gt; 
      &lt;D:prop&gt; 
        &lt;B:salary/&gt; 
      &lt;/D:prop&gt; 
      &lt;D:status&gt;HTTP/1.1 403 Forbidden&lt;/D:status&gt; 
    &lt;/D:propstat&gt; 
  &lt;/D:response&gt; 
&lt;/D:multistatus&gt; 
</pre></div></section></section><section id="REPORT_principal-search-property-set"><h3 id="rfc.section.9.5"><a href="#rfc.section.9.5">9.5.</a>&nbsp;<a href="#REPORT_principal-search-property-set">DAV:principal-search-property-set REPORT</a></h3><div id="rfc.section.9.5.p.1"><p>The DAV:principal-search-property-set REPORT identifies those properties that may be searched using the DAV:principal-property-search REPORT (defined in <a href="#REPORT_principal-property-search" title="DAV:principal-property-search REPORT">Section&nbsp;9.4</a>).<a class="self" href="#rfc.section.9.5.p.1">&para;</a></p></div><div id="rfc.section.9.5.p.2"><p>Servers <em class="bcp14">MUST</em> support the DAV:principal-search-property-set REPORT on all collections identified in the value of a DAV:principal-collection-set property.<a class="self" href="#rfc.section.9.5.p.2">&para;</a></p></div><div id="rfc.section.9.5.p.3"><p>An access control protocol user agent could use the results of the DAV:principal-search-property-set REPORT to present a query interface to the user for retrieving principals.<a class="self" href="#rfc.section.9.5.p.3">&para;</a></p></div><div id="rfc.section.9.5.p.4"><p>Support for this report is <em class="bcp14">REQUIRED</em>.<a class="self" href="#rfc.section.9.5.p.4">&para;</a></p></div><div id="rfc.section.9.5.p.5"><ul class="empty"><li><b>Implementation Note:</b> Some clients will have only limited screen real estate for the display of lists of searchable properties. In this case, a user might appreciate having the most frequently searched properties be displayed on-screen, rather than having to scroll through a long list of searchable properties. One mechanism for signaling the most frequently searched properties is to return them towards the start of a list of properties. A client can then preferentially display the list of properties in order, increasing the likelihood that the most frequently searched properties will appear on-screen, and will not require scrolling for their selection.</li></ul></div><div id="rfc.section.9.5.p.6"><p><b>Marshalling:</b> <a class="self" href="#rfc.section.9.5.p.6">&para;</a></p><ul class="empty"><li>The request body <em class="bcp14">MUST</em> be an empty DAV:principal-search-property-set XML element.</li><li>This report is only defined when the Depth header has value "0"; other values result in a 400 (Bad Request) error response. Note that <a href="#RFC3253" id="rfc.xref.RFC3253.10"><cite title="Versioning Extensions to WebDAV">[RFC3253]</cite></a>, <a href="https://tools.ietf.org/html/rfc3253#section-3.6">Section 3.6</a>, states that if the Depth header is not present, it defaults to a value of "0".</li><li>The response body <em class="bcp14">MUST</em> be a DAV:principal-search-property-set XML element, containing a DAV:principal-search-property XML element for each property that may be searched with the DAV:principal-property-search REPORT. A server <em class="bcp14">MAY</em> limit its response to just a subset of the searchable properties, such as those likely to be useful to an interactive access control client. <span id="rfc.figure.u.93"><pre class="inline">   &lt;!ELEMENT principal-search-property-set
    (principal-search-property*) &gt; 
</pre></span> </li><li>Each DAV:principal-search-property XML element contains exactly one searchable property, and a description of the property. <span id="rfc.figure.u.94"><pre class="inline">   &lt;!ELEMENT principal-search-property (prop, description) &gt; 
</pre></span> </li><li>The DAV:prop element contains one principal property on which the server is able to perform a DAV:principal-property-search REPORT. <span id="rfc.figure.u.95"><pre class="inline">   prop: see RFC 2518, Section 12.11 
</pre></span> </li><li>The description element is a human-readable description of what information this property represents. Servers <em class="bcp14">MUST</em> indicate the human language of the description using the xml:lang attribute and <em class="bcp14">SHOULD</em> consider the HTTP Accept-Language request header when selecting one of multiple available languages. <span id="rfc.figure.u.96"><pre class="inline">   &lt;!ELEMENT description #PCDATA &gt; 
</pre></span> </li></ul></div><section id="n-example--dav-principal-search-property-set-report"><h4 id="rfc.section.9.5.1"><a href="#rfc.section.9.5.1">9.5.1.</a>&nbsp;<a href="#n-example--dav-principal-search-property-set-report">Example: DAV:principal-search-property-set REPORT</a></h4><div id="rfc.section.9.5.1.p.1"><p>In this example, the client determines the set of searchable principal properties by requesting the DAV:principal-search-property-set REPORT on the root of the server's principal URL collection set, identified by http://www.example.com/users/.<a class="self" href="#rfc.section.9.5.1.p.1">&para;</a></p></div><div id="rfc.figure.u.97"><p>&gt;&gt; Request &lt;&lt;</p><pre class="text2">REPORT /users/ HTTP/1.1 
Host: www.example.com 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 
Accept-Language: en, de 
Authorization: BASIC d2FubmFtYWs6cGFzc3dvcmQ= 
Depth: 0 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:principal-search-property-set xmlns:D="DAV:"/&gt; 
</pre></div><div id="rfc.figure.u.98"><p>&gt;&gt; Response &lt;&lt;</p><pre class="text">HTTP/1.1 200 OK 
Content-Type: text/xml; charset="utf-8" 
Content-Length: xxx 

&lt;?xml version="1.0" encoding="utf-8" ?&gt; 
&lt;D:principal-search-property-set xmlns:D="DAV:"&gt; 
  &lt;D:principal-search-property&gt; 
    &lt;D:prop&gt; 
      &lt;D:displayname/&gt; 
    &lt;/D:prop&gt; 
    &lt;D:description xml:lang="en"&gt;Full name&lt;/D:description&gt; 
  &lt;/D:principal-search-property&gt; 
  &lt;D:principal-search-property&gt; 
    &lt;D:prop xmlns:B="http://BigCorp.com/ns/"&gt; 
      &lt;B:title/&gt; 
    &lt;/D:prop&gt; 
    &lt;D:description xml:lang="en"&gt;Job title&lt;/D:description&gt; 
  &lt;/D:principal-search-property&gt; 
&lt;/D:principal-search-property-set&gt; 
</pre></div></section></section></section><section id="xml.processing"><h2 id="rfc.section.10"><a href="#rfc.section.10">10.</a>&nbsp;<a href="#xml.processing">XML Processing</a></h2><div id="rfc.section.10.p.1"><p>Implementations of this specification <em class="bcp14">MUST</em> support the XML element ignore rule, as specified in <a href="https://tools.ietf.org/html/rfc2518#section-23.3.2">Section 23.3.2</a> of <a href="#RFC2518" id="rfc.xref.RFC2518.12"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>, and the XML Namespace recommendation <a href="#REC-XML-NAMES" id="rfc.xref.REC-XML-NAMES.1"><cite title="Namespaces in XML">[REC-XML-NAMES]</cite></a>.<a class="self" href="#rfc.section.10.p.1">&para;</a></p></div><div id="rfc.section.10.p.2"><p>Note that use of the DAV namespace is reserved for XML elements and property names defined in a standards-track or Experimental IETF RFC.<a class="self" href="#rfc.section.10.p.2">&para;</a></p></div></section><section id="internationalization.considerations"><h2 id="rfc.section.11"><a href="#rfc.section.11">11.</a>&nbsp;<a href="#internationalization.considerations">Internationalization Considerations</a></h2><div id="rfc.section.11.p.1"><p>In this specification, the only human-readable content can be found in the description XML element, found within the DAV:supported-privilege-set property. This element contains a human-readable description of the capabilities controlled by a privilege. As a result, the description element must be capable of representing descriptions in multiple character sets. Since the description element is found within a WebDAV property, it is represented on the wire as XML <a href="#REC-XML" id="rfc.xref.REC-XML.2"><cite title="Extensible Markup Language (XML) 1.0 (Third Edition)">[REC-XML]</cite></a>, and hence can leverage XML's language tagging and character set encoding capabilities. Specifically, XML processors at minimum must be able to read XML elements encoded using the UTF-8 <a href="#RFC3629" id="rfc.xref.RFC3629.1"><cite title="UTF-8, a transformation format of ISO 10646">[RFC3629]</cite></a> encoding of the ISO 10646 multilingual plane. XML examples in this specification demonstrate use of the charset parameter of the Content-Type header, as defined in <a href="#RFC3023" id="rfc.xref.RFC3023.1"><cite title="XML Media Types">[RFC3023]</cite></a>, as well as the XML "encoding" attribute, which together provide charset identification information for MIME and XML processors. Futhermore, this specification requires server implementations to tag description fields with the xml:lang attribute (see Section 2.12 of <a href="#REC-XML" id="rfc.xref.REC-XML.3"><cite title="Extensible Markup Language (XML) 1.0 (Third Edition)">[REC-XML]</cite></a>), which specifies the human language of the description. Additionally, server implementations should take into account the value of the Accept-Language HTTP header to determine which description string to return.<a class="self" href="#rfc.section.11.p.1">&para;</a></p></div><div id="rfc.section.11.p.2"><p>For XML elements other than the description element, it is expected that implementations will treat the property names, privilege names, and values as tokens, and convert these tokens into human-readable text in the user's language and character set when displayed to a person. Only a generic WebDAV property display utility would display these values in their raw form to a human user.<a class="self" href="#rfc.section.11.p.2">&para;</a></p></div><div id="rfc.section.11.p.3"><p>For error reporting, we follow the convention of HTTP/1.1 status codes, including with each status code a short, English description of the code (e.g., 200 (OK)). While the possibility exists that a poorly crafted user agent would display this message to a user, internationalized applications will ignore this message, and display an appropriate message in the user's language and character set.<a class="self" href="#rfc.section.11.p.3">&para;</a></p></div><div id="rfc.section.11.p.4"><p>Further internationalization considerations for this protocol are described in the WebDAV Distributed Authoring protocol specification <a href="#RFC2518" id="rfc.xref.RFC2518.13"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>.<a class="self" href="#rfc.section.11.p.4">&para;</a></p></div></section><section id="security.considerations"><h2 id="rfc.section.12"><a href="#rfc.section.12">12.</a>&nbsp;<a href="#security.considerations">Security Considerations</a></h2><div id="rfc.section.12.p.1"><p>Applications and users of this access control protocol should be aware of several security considerations, detailed below. In addition to the discussion in this document, the security considerations detailed in the HTTP/1.1 specification <a href="#RFC2616" id="rfc.xref.RFC2616.4"><cite title="Hypertext Transfer Protocol -- HTTP/1.1">[RFC2616]</cite></a>, the WebDAV Distributed Authoring Protocol specification <a href="#RFC2518" id="rfc.xref.RFC2518.14"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>, and the XML Media Types specification <a href="#RFC3023" id="rfc.xref.RFC3023.2"><cite title="XML Media Types">[RFC3023]</cite></a> should be considered in a security analysis of this protocol.<a class="self" href="#rfc.section.12.p.1">&para;</a></p></div><section id="n-increased-risk-of-compromised-users"><h3 id="rfc.section.12.1"><a href="#rfc.section.12.1">12.1.</a>&nbsp;<a href="#n-increased-risk-of-compromised-users">Increased Risk of Compromised Users</a></h3><div id="rfc.section.12.1.p.1"><p>In the absence of a mechanism for remotely manipulating access control lists, if a single user's authentication credentials are compromised, only those resources for which the user has access permission can be read, modified, moved, or deleted. With the introduction of this access control protocol, if a single compromised user has the ability to change ACLs for a broad range of other users (e.g., a super-user), the number of resources that could be altered by a single compromised user increases. This risk can be mitigated by limiting the number of people who have write-acl privileges across a broad range of resources.<a class="self" href="#rfc.section.12.1.p.1">&para;</a></p></div></section><section id="n-risks-of-the-dav-read-acl-and-dav-current-user-privilege-set-privileges"><h3 id="rfc.section.12.2"><a href="#rfc.section.12.2">12.2.</a>&nbsp;<a href="#n-risks-of-the-dav-read-acl-and-dav-current-user-privilege-set-privileges">Risks of the DAV:read-acl and DAV:current-user-privilege-set Privileges</a></h3><div id="rfc.section.12.2.p.1"><p>The ability to read the access privileges (stored in the DAV:acl property), or the privileges permitted the currently authenticated user (stored in the DAV:current-user-privilege-set property) on a resource may seem innocuous, since reading an ACL cannot possibly affect the resource's state. However, if all resources have world-readable ACLs, it is possible to perform an exhaustive search for those resources that have inadvertently left themselves in a vulnerable state, such as being world-writable. In particular, the property retrieval method PROPFIND, executed with Depth infinity on an entire hierarchy, is a very efficient way to retrieve the DAV:acl or DAV:current-user-privilege-set properties. Once found, this vulnerability can be exploited by a denial of service attack in which the open resource is repeatedly overwritten. Alternately, writable resources can be modified in undesirable ways.<a class="self" href="#rfc.section.12.2.p.1">&para;</a></p></div><div id="rfc.section.12.2.p.2"><p>To reduce this risk, read-acl privileges should not be granted to unauthenticated principals, and restrictions on read-acl and read-current-user-privilege-set privileges for authenticated principals should be carefully analyzed when deploying this protocol. Access to the current-user-privilege-set property will involve a tradeoff of usability versus security. When the current-user-privilege-set is visible, user interfaces are expected to provide enhanced information concerning permitted and restricted operations, yet this information may also indicate a vulnerability that could be exploited. Deployment of this protocol will need to evaluate this tradeoff in light of the requirements of the deployment environment.<a class="self" href="#rfc.section.12.2.p.2">&para;</a></p></div></section><section id="n-no-foreknowledge-of-initial-acl"><h3 id="rfc.section.12.3"><a href="#rfc.section.12.3">12.3.</a>&nbsp;<a href="#n-no-foreknowledge-of-initial-acl">No Foreknowledge of Initial ACL</a></h3><div id="rfc.section.12.3.p.1"><p>In an effort to reduce protocol complexity, this protocol specification intentionally does not address the issue of how to manage or discover the initial ACL that is placed upon a resource when it is created. The only way to discover the initial ACL is to create a new resource, then retrieve the value of the DAV:acl property. This assumes the principal creating the resource also has been granted the DAV:read-acl privilege.<a class="self" href="#rfc.section.12.3.p.1">&para;</a></p></div><div id="rfc.section.12.3.p.2"><p>As a result, it is possible that a principal could create a resource, and then discover that its ACL grants privileges that are undesirable. Furthermore, this protocol makes it possible (though unlikely) that the creating principal could be unable to modify the ACL, or even delete the resource. Even when the ACL can be modified, there will be a short period of time when the resource exists with the initial ACL before its new ACL can be set.<a class="self" href="#rfc.section.12.3.p.2">&para;</a></p></div><div id="rfc.section.12.3.p.3"><p>Several factors mitigate this risk. Human principals are often aware of the default access permissions in their editing environments and take this into account when writing information. Furthermore, default privilege policies are usually very conservative, limiting the privileges granted by the initial ACL.<a class="self" href="#rfc.section.12.3.p.3">&para;</a></p></div></section></section><section id="authentication"><h2 id="rfc.section.13"><a href="#rfc.section.13">13.</a>&nbsp;<a href="#authentication">Authentication</a></h2><div id="rfc.section.13.p.1"><p>Authentication mechanisms defined for use with HTTP and WebDAV also apply to this WebDAV Access Control Protocol, in particular the Basic and Digest authentication mechanisms defined in <a href="#RFC2617" id="rfc.xref.RFC2617.2"><cite title="HTTP Authentication: Basic and Digest Access Authentication">[RFC2617]</cite></a>. Implementation of the ACL spec requires that Basic authentication, if used, <em class="bcp14">MUST</em> only be supported over secure transport such as TLS.<a class="self" href="#rfc.section.13.p.1">&para;</a></p></div></section><section id="n-iana-considerations"><h2 id="rfc.section.14"><a href="#rfc.section.14">14.</a>&nbsp;<a href="#n-iana-considerations">IANA Considerations</a></h2><div id="rfc.section.14.p.1"><p>This document uses the namespace defined by <a href="#RFC2518" id="rfc.xref.RFC2518.15"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a> for XML elements. That is, this specification uses the "DAV:" URI namespace, previously registered in the URI schemes registry. All other IANA considerations mentioned in <a href="#RFC2518" id="rfc.xref.RFC2518.16"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a> are also applicable to this specification.<a class="self" href="#rfc.section.14.p.1">&para;</a></p></div></section><section id="n-acknowledgements"><h2 id="rfc.section.15"><a href="#rfc.section.15">15.</a>&nbsp;<a href="#n-acknowledgements">Acknowledgements</a></h2><div id="rfc.section.15.p.1"><p>This protocol is the collaborative product of the WebDAV ACL design team: Bernard Chester, Geoff Clemm, Anne Hopkins, Barry Lind, Sean Lyndersay, Eric Sedlar, Greg Stein, and Jim Whitehead. The authors are grateful for the detailed review and comments provided by Jim Amsden, Dylan Barrell, Gino Basso, Murthy Chintalapati, Lisa Dusseault, Stefan Eissing, Tim Ellison, Yaron Goland, Dennis Hamilton, Laurie Harper, Eckehard Hermann, Ron Jacobs, Chris Knight, Remy Maucherat, Larry Masinter, Joe Orton, Peter Raymond, and Keith Wannamaker. We thank Keith Wannamaker for the initial text of the principal property search sections. Prior work on WebDAV access control protocols has been performed by Yaron Goland, Paul Leach, Lisa Dusseault, Howard Palmer, and Jon Radoff. We would like to acknowledge the foundation laid for us by the authors of the DeltaV, WebDAV and HTTP protocols upon which this protocol is layered, and the invaluable feedback from the WebDAV working group.<a class="self" href="#rfc.section.15.p.1">&para;</a></p></div></section><section id="rfc.references"><h2 id="rfc.section.16"><a href="#rfc.section.16">16.</a> References</h2><section id="rfc.references.1"><h3 id="rfc.section.16.1"><a href="#rfc.section.16.1">16.1.</a> Normative References</h3><dl class="reference"><dt id="REC-XML">[REC-XML]</dt><dd><a href="mailto:tbray@textuality.com">Bray, T.</a>, <a href="mailto:jeanpa@microsoft.com">Paoli, J.</a>, <a href="mailto:cmsmcq@uic.edu">Sperberg-McQueen, C.</a>, <a href="mailto:eve.maler@east.sun.com">Maler, E.</a>, and <a href="mailto:francois@yergeau.com">F. Yergeau</a>, &#8220;<a href="http://www.w3.org/TR/2004/REC-xml-20040204">Extensible Markup Language (XML) 1.0 (Third Edition)</a>&#8221;, W3C&nbsp;REC-xml-20040204, February&nbsp;2004, &lt;<a href="http://www.w3.org/TR/2004/REC-xml-20040204">http://www.w3.org/TR/2004/REC-xml-20040204</a>&gt;.</dd><dt id="REC-XML-INFOSET">[REC-XML-INFOSET]</dt><dd><a href="mailto:jcowan@reutershealth.com">Cowan, J.</a> and <a href="mailto:richard@cogsci.ed.ac.uk">R. Tobin</a>, &#8220;<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/">XML Information Set (Second Edition)</a>&#8221;, W3C REC&nbsp;REC-xml-infoset-20040204, February&nbsp;2004, &lt;<a href="http://www.w3.org/TR/2004/REC-xml-infoset-20040204/">http://www.w3.org/TR/2004/REC-xml-infoset-20040204/</a>&gt;.</dd><dt id="REC-XML-NAMES">[REC-XML-NAMES]</dt><dd><a href="mailto:tbray@textuality.com">Bray, T.</a>, <a href="mailto:dmh@corp.hp.com">Hollander, D.</a>, and <a href="mailto:andrewl@microsoft.com">A. Layman</a>, &#8220;<a href="http://www.w3.org/TR/1999/REC-xml-names-19990114">Namespaces in XML</a>&#8221;, W3C REC&nbsp;REC-xml-names-19990114, January&nbsp;1999, &lt;<a href="http://www.w3.org/TR/1999/REC-xml-names-19990114">http://www.w3.org/TR/1999/REC-xml-names-19990114</a>&gt;.</dd><dt id="RFC2119">[RFC2119]</dt><dd><a href="mailto:sob@harvard.edu">Bradner, S.</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>&#8221;, BCP&nbsp;14, RFC&nbsp;2119, March&nbsp;1997.</dd><dt id="RFC2518">[RFC2518]</dt><dd><a href="mailto:yarong@microsoft.com">Goland, Y.</a>, <a href="mailto:ejw@ics.uci.edu">Whitehead, E.</a>, <a href="mailto:asad@netscape.com">Faizi, A.</a>, <a href="mailto:srcarter@novell.com">Carter, S.</a>, and <a href="mailto:dcjensen@novell.com">D. Jensen</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2518">HTTP Extensions for Distributed Authoring -- WEBDAV</a>&#8221;, RFC&nbsp;2518, February&nbsp;1999.</dd><dt id="RFC2616">[RFC2616]</dt><dd><a href="mailto:fielding@ics.uci.edu">Fielding, R.</a>, <a href="mailto:jg@w3.org">Gettys, J.</a>, <a href="mailto:mogul@wrl.dec.com">Mogul, J.</a>, <a href="mailto:frystyk@w3.org">Frystyk, H.</a>, <a href="mailto:masinter@parc.xerox.com">Masinter, L.</a>, <a href="mailto:paulle@microsoft.com">Leach, P.</a>, and <a href="mailto:timbl@w3.org">T. Berners-Lee</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2616">Hypertext Transfer Protocol -- HTTP/1.1</a>&#8221;, RFC&nbsp;2616, June&nbsp;1999.</dd><dt id="RFC2617">[RFC2617]</dt><dd><a href="mailto:john@math.nwu.edu">Franks, J.</a>, <a href="mailto:pbaker@verisign.com">Hallam-Baker, P.</a>, <a href="mailto:jeff@AbiSource.com">Hostetler, J.</a>, <a href="mailto:lawrence@agranat.com">Lawrence, S.</a>, <a href="mailto:paulle@microsoft.com">Leach, P.</a>, Luotonen, A., and <a href="mailto:stewart@OpenMarket.com">L. Stewart</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2617">HTTP Authentication: Basic and Digest Access Authentication</a>&#8221;, RFC&nbsp;2617, June&nbsp;1999.</dd><dt id="RFC3023">[RFC3023]</dt><dd><a href="mailto:mmurata@trl.ibm.co.jp">Makoto, M.</a>, <a href="mailto:simonstl@simonstl.com">St.Laurent, S.</a>, and <a href="mailto:dan@dankohn.com">D. Kohn</a>, &#8220;<a href="https://tools.ietf.org/html/rfc3023">XML Media Types</a>&#8221;, RFC&nbsp;3023, January&nbsp;2001.</dd><dt id="RFC3253">[RFC3253]</dt><dd><a href="mailto:geoffrey.clemm@rational.com">Clemm, G.</a>, <a href="mailto:jamsden@us.ibm.com">Amsden, J.</a>, <a href="mailto:tim_ellison@uk.ibm.com">Ellison, T.</a>, <a href="mailto:ckaler@microsoft.com">Kaler, C.</a>, and <a href="mailto:ejw@cse.ucsc.edu">J. Whitehead</a>, &#8220;<a href="https://tools.ietf.org/html/rfc3253">Versioning Extensions to WebDAV</a>&#8221;, RFC&nbsp;3253, March&nbsp;2002.</dd><dt id="RFC3530">[RFC3530]</dt><dd><a href="mailto:spencer.shepler@sun.com">Shepler, S., Ed.</a>, <a href="mailto:brent.callaghan@sun.com">Callaghan, B.</a>, <a href="mailto:david.robinson@sun.com">Robinson, D.</a>, <a href="mailto:robert.thurlow@sun.com">Thurlow, R.</a>, <a href="mailto:beame@bws.com">Beame, C.</a>, <a href="mailto:mike@eisler.com">Eisler, M.</a>, and <a href="mailto:dnoveck@netapp.com">D. Noveck</a>, &#8220;<a href="https://tools.ietf.org/html/rfc3530">Network File System (NFS) version 4 Protocol</a>&#8221;, RFC&nbsp;3530, April&nbsp;2003.</dd><dt id="RFC3629">[RFC3629]</dt><dd><a href="mailto:fyergeau@alis.com">Yergeau, F.</a>, &#8220;<a href="https://tools.ietf.org/html/rfc3629">UTF-8, a transformation format of ISO 10646</a>&#8221;, RFC&nbsp;3629, STD&nbsp;63, November&nbsp;2003.</dd></dl></section><section id="rfc.references.2"><h3 id="rfc.section.16.2"><a href="#rfc.section.16.2">16.2.</a> Informative References</h3><dl class="reference"><dt id="RFC2251">[RFC2251]</dt><dd><a href="mailto:M.Wahl@critical-angle.com">Wahl, M.</a>, <a href="mailto:howes@netscape.com">Howes, T.</a>, and <a href="mailto:S.Kille@isode.com">S. Kille</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2251">Lightweight Directory Access Protocol (v3)</a>&#8221;, RFC&nbsp;2251, December&nbsp;1997.</dd><dt id="RFC2255">[RFC2255]</dt><dd><a href="mailto:howes@netscape.com">Howes, T.</a> and <a href="mailto:mcs@netscape.com">M. Smith</a>, &#8220;<a href="https://tools.ietf.org/html/rfc2255">The LDAP URL Format</a>&#8221;, RFC&nbsp;2255, December&nbsp;1997.</dd><dt id="UNICODE4">[UNICODE4]</dt><dd>The Unicode Consortium, &#8220;<a href="http://www.unicode.org/versions/Unicode4.0.0/">The Unicode Standard - Version 4.0</a>&#8221;, Addison-Wesley, August&nbsp;2003, &lt;<a href="http://www.unicode.org/versions/Unicode4.0.0/">http://www.unicode.org/versions/Unicode4.0.0/</a>&gt;.<br><a href="urn:isbn:0321185781">ISBN 0321185781</a>.</dd></dl></section></section><section id="webdav.xml.document.type.definition.addendum"><h2 id="rfc.section.A" class="np"><a href="#rfc.section.A">A.</a>&nbsp;<a href="#webdav.xml.document.type.definition.addendum">WebDAV XML Document Type Definition Addendum</a></h2><div id="rfc.section.A.p.1"><p>All XML elements defined in this Document Type Definition (DTD) belong to the DAV namespace. This DTD should be viewed as an addendum to the DTD provided in <a href="#RFC2518" id="rfc.xref.RFC2518.17"><cite title="HTTP Extensions for Distributed Authoring -- WEBDAV">[RFC2518]</cite></a>, <a href="https://tools.ietf.org/html/rfc2518#section-23.1">Section 23.1</a>.<a class="self" href="#rfc.section.A.p.1">&para;</a></p></div><div id="rfc.figure.u.99"><p>&lt;!-- Privileges -- (<a href="#privileges" title="Privileges">Section&nbsp;3</a>)&gt;</p><pre class="inline">&lt;!ELEMENT read EMPTY&gt; 
&lt;!ELEMENT write EMPTY&gt; 
&lt;!ELEMENT write-properties EMPTY&gt; 
&lt;!ELEMENT write-content EMPTY&gt; 
&lt;!ELEMENT unlock EMPTY&gt; 
&lt;!ELEMENT read-acl EMPTY&gt; 
&lt;!ELEMENT read-current-user-privilege-set EMPTY&gt; 
&lt;!ELEMENT write-acl EMPTY&gt; 
&lt;!ELEMENT bind EMPTY&gt; 
&lt;!ELEMENT unbind EMPTY&gt; 
&lt;!ELEMENT all EMPTY&gt; 
</pre></div><div id="rfc.figure.u.100"><p>&lt;!-- Principal Properties (<a href="#principal.properties" title="Principal Properties">Section&nbsp;4</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT principal EMPTY&gt; 

&lt;!ELEMENT alternate-URI-set (href*)&gt; 
&lt;!ELEMENT principal-URL (href)&gt; 
&lt;!ELEMENT group-member-set (href*)&gt; 
&lt;!ELEMENT group-membership (href*)&gt; 
</pre></div><div id="rfc.section.A.p.2"><p>&lt;!-- Access Control Properties (<a href="#access.control.properties" title="Access Control Properties">Section&nbsp;5</a>) --&gt;<a class="self" href="#rfc.section.A.p.2">&para;</a></p></div><div id="rfc.figure.u.101"><p>&lt;!-- DAV:owner Property (<a href="#PROPERTY_owner" title="DAV:owner">Section&nbsp;5.1</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT owner (href?)&gt; 
</pre></div><div id="rfc.figure.u.102"><p>&lt;!-- DAV:group Property (<a href="#PROPERTY_group" title="DAV:group">Section&nbsp;5.2</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT group (href?)&gt; 
</pre></div><div id="rfc.figure.u.103"><p>&lt;!-- DAV:supported-privilege-set Property (<a href="#PROPERTY_supported-privilege-set" title="DAV:supported-privilege-set">Section&nbsp;5.3</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT supported-privilege-set (supported-privilege*)&gt; 
&lt;!ELEMENT supported-privilege 
 (privilege, abstract?, description, supported-privilege*)&gt; 

&lt;!ELEMENT privilege ANY&gt; 
&lt;!ELEMENT abstract EMPTY&gt; 
&lt;!ELEMENT description #PCDATA&gt;  
</pre></div><div id="rfc.figure.u.104"><p>&lt;!-- DAV:current-user-privilege-set Property (<a href="#PROPERTY_current-user-privilege-set" title="DAV:current-user-privilege-set">Section&nbsp;5.4</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT current-user-privilege-set (privilege*)&gt; 
</pre></div><div id="rfc.figure.u.105"><p>&lt;!-- DAV:acl Property (<a href="#PROPERTY_acl" title="DAV:acl">Section&nbsp;5.5</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT acl (ace)* &gt; 
&lt;!ELEMENT ace ((principal | invert), (grant|deny), protected?, 
 inherited?)&gt; 

&lt;!ELEMENT principal (href) 
 | all | authenticated | unauthenticated 
 | property | self)&gt; 

&lt;!ELEMENT all EMPTY&gt; 
&lt;!ELEMENT authenticated EMPTY&gt; 
&lt;!ELEMENT unauthenticated EMPTY&gt; 
&lt;!ELEMENT property ANY&gt; 
&lt;!ELEMENT self EMPTY&gt; 

&lt;!ELEMENT invert principal&gt; 

&lt;!ELEMENT grant (privilege+)&gt; 
&lt;!ELEMENT deny (privilege+)&gt; 
&lt;!ELEMENT privilege ANY&gt; 

&lt;!ELEMENT protected EMPTY&gt; 

&lt;!ELEMENT inherited (href)&gt; 
</pre></div><div id="rfc.figure.u.106"><p>&lt;!-- DAV:acl-restrictions Property (<a href="#PROPERTY_acl-restrictions" title="DAV:acl-restrictions">Section&nbsp;5.6</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT acl-restrictions (grant-only?, no-invert?,
 deny-before-grant?, required-principal?)&gt; 

&lt;!ELEMENT grant-only EMPTY&gt; 
&lt;!ELEMENT no-invert EMPTY&gt; 
&lt;!ELEMENT deny-before-grant EMPTY&gt; 

&lt;!ELEMENT required-principal 
 (all? | authenticated? | unauthenticated? | self? | href* 
 |property*)&gt; 
</pre></div><div id="rfc.figure.u.107"><p>&lt;!-- DAV:inherited-acl-set Property (<a href="#PROPERTY_inherited-acl-set" title="DAV:inherited-acl-set">Section&nbsp;5.7</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT inherited-acl-set (href*)&gt; 
</pre></div><div id="rfc.figure.u.108"><p>&lt;!-- DAV:principal-collection-set Property (<a href="#PROPERTY_principal-collection-set" title="DAV:principal-collection-set">Section&nbsp;5.8</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT principal-collection-set (href*)&gt; 
</pre></div><div id="rfc.figure.u.109"><p>&lt;!-- Access Control and Existing Methods (<a href="#access.control.and.existing.methods" title="Access Control and existing methods">Section&nbsp;7</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT need-privileges (resource)* &gt;
&lt;!ELEMENT resource ( href, privilege )
</pre></div><div id="rfc.figure.u.110"><p>&lt;!-- ACL method preconditions (<a href="#acl.preconditions" title="ACL Preconditions">Section&nbsp;8.1.1</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT no-ace-conflict EMPTY&gt; 
&lt;!ELEMENT no-protected-ace-conflict EMPTY&gt; 
&lt;!ELEMENT no-inherited-ace-conflict EMPTY&gt; 
&lt;!ELEMENT limited-number-of-aces EMPTY&gt; 
&lt;!ELEMENT grant-only EMPTY&gt; 
&lt;!ELEMENT no-invert EMPTY&gt; 
&lt;!ELEMENT deny-before-grant EMPTY&gt; 
&lt;!ELEMENT no-abstract EMPTY&gt; 
&lt;!ELEMENT not-supported-privilege EMPTY&gt; 
&lt;!ELEMENT missing-required-principal EMPTY&gt; 
&lt;!ELEMENT recognized-principal EMPTY&gt; 
&lt;!ELEMENT allowed-principal EMPTY&gt; 
</pre></div><div id="rfc.figure.u.111"><p>&lt;!-- REPORTs (<a href="#access.control.reports" title="Access Control Reports">Section&nbsp;9</a>) --&gt;</p><pre class="inline">&lt;!ELEMENT acl-principal-prop-set ANY&gt; 
ANY value: a sequence of one or more elements, with at most one 
DAV:prop element. 

&lt;!ELEMENT principal-match ((principal-property | self), prop?)&gt; 
&lt;!ELEMENT principal-property ANY&gt; 
ANY value: an element whose value identifies a property. The 
expectation is the value of the named property typically contains 
an href element that contains the URI of a principal 
&lt;!ELEMENT self EMPTY&gt; 

&lt;!ELEMENT principal-property-search ((property-search+), prop?) &gt; 
&lt;!ELEMENT property-search (prop, match) &gt; 
&lt;!ELEMENT match #PCDATA &gt; 

&lt;!ELEMENT principal-search-property-set (
 principal-search-property*) &gt; 
&lt;!ELEMENT principal-search-property (prop, description) &gt; 
&lt;!ELEMENT description #PCDATA &gt; 
</pre></div></section><section id="n-webdav-method-privilege-table--normative-"><h2 id="rfc.section.B"><a href="#rfc.section.B">B.</a>&nbsp;<a href="#n-webdav-method-privilege-table--normative-">WebDAV Method Privilege Table (Normative)</a></h2><div id="rfc.section.B.p.1"><p>The following table of WebDAV methods (as defined in RFC 2518, 2616, and 3253) clarifies which privileges are required for access for each method. Note that the privileges listed, if denied, <em class="bcp14">MUST</em> cause access to be denied. However, given that a specific implementation <em class="bcp14">MAY</em> define an additional custom privilege to control access to existing methods, having all of the indicated privileges does not mean that access will be granted. Note that lack of the indicated privileges does not imply that access will be denied, since a particular implementation may use a sub-privilege aggregated under the indicated privilege to control access. Privileges required refer to the current resource being processed unless otherwise specified.<a class="self" href="#rfc.section.B.p.1">&para;</a></p></div><div id="rfc.table.u.1" class="tt"><table class="tt full tcenter"><thead><tr><th>METHOD</th><th>PRIVILEGES</th></tr></thead><tbody><tr><td class="left">GET</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a></td></tr><tr><td class="left">HEAD</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a></td></tr><tr><td class="left">OPTIONS</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a></td></tr><tr><td class="left">PUT (target exists)</td><td class="left"><a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a> on target resource</td></tr><tr><td class="left">PUT (no target exists)</td><td class="left"><a href="#PRIVILEGE_bind">&lt;D:bind&gt;</a> on parent collection of target</td></tr><tr><td class="left">PROPPATCH</td><td class="left"><a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a></td></tr><tr><td class="left">ACL</td><td class="left"><a href="#PRIVILEGE_write-acl">&lt;D:write-acl&gt;</a></td></tr><tr><td class="left">PROPFIND</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a> (plus <a href="#PRIVILEGE_read-acl">&lt;D:read-acl&gt;</a> and <a href="#PRIVILEGE_read-current-user-privilege-set">&lt;D:read-current-user-privilege-set&gt;</a> as needed)</td></tr><tr><td class="left">COPY (target exists)</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a>, <a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a> and <a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a> on target resource</td></tr><tr><td class="left">COPY (no target exists)</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a>, <a href="#PRIVILEGE_bind">&lt;D:bind&gt;</a> on target collection</td></tr><tr><td class="left">MOVE (no target exists)</td><td class="left"><a href="#PRIVILEGE_unbind">&lt;D:unbind&gt;</a> on source collection and <a href="#PRIVILEGE_bind">&lt;D:bind&gt;</a> on target collection</td></tr><tr><td class="left">MOVE (target exists)</td><td class="left">As above, plus <a href="#PRIVILEGE_unbind">&lt;D:unbind&gt;</a> on the target collection</td></tr><tr><td class="left">DELETE</td><td class="left"><a href="#PRIVILEGE_unbind">&lt;D:unbind&gt;</a> on parent collection</td></tr><tr><td class="left">LOCK (target exists)</td><td class="left"><a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a></td></tr><tr><td class="left">LOCK (no target exists)</td><td class="left"><a href="#PRIVILEGE_bind">&lt;D:bind&gt;</a> on parent collection</td></tr><tr><td class="left">MKCOL</td><td class="left"><a href="#PRIVILEGE_bind">&lt;D:bind&gt;</a> on parent collection</td></tr><tr><td class="left">UNLOCK</td><td class="left"><a href="#PRIVILEGE_unlock">&lt;D:unlock&gt;</a></td></tr><tr><td class="left">CHECKOUT</td><td class="left"><a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a></td></tr><tr><td class="left">CHECKIN</td><td class="left"><a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a></td></tr><tr><td class="left">REPORT</td><td class="left"><a href="#PRIVILEGE_read">&lt;D:read&gt;</a> (on all referenced resources)</td></tr><tr><td class="left">VERSION-CONTROL</td><td class="left"><a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a></td></tr><tr><td class="left">MERGE</td><td class="left"><a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a></td></tr><tr><td class="left">MKWORKSPACE</td><td class="left"><a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a> on parent collection</td></tr><tr><td class="left">BASELINE-CONTROL</td><td class="left"><a href="#PRIVILEGE_write-properties">&lt;D:write-properties&gt;</a> and <a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a></td></tr><tr><td class="left">MKACTIVITY</td><td class="left"><a href="#PRIVILEGE_write-content">&lt;D:write-content&gt;</a> on parent collection</td></tr></tbody></table></div></section><section id="rfc.index"><h2><a href="#rfc.index">Index</a></h2><p class="noprint"><a href="#rfc.index.A">A</a> <a href="#rfc.index.C">C</a> <a href="#rfc.index.D">D</a> <a href="#rfc.index.G">G</a> <a href="#rfc.index.I">I</a> <a href="#rfc.index.M">M</a> <a href="#rfc.index.P">P</a> <a href="#rfc.index.R">R</a> <a href="#rfc.index.U">U</a> </p><div class="print2col"><ul class="ind"><li><a id="rfc.index.A" href="#rfc.index.A"><b>A</b></a><ul><li>abstract&nbsp;&nbsp;<a href="#rfc.iref.a.2"><b>1.1</b></a></li><li>access control element&nbsp;&nbsp;<a href="#rfc.iref.a.5"><b>1.1</b></a></li><li>access control list&nbsp;&nbsp;<a href="#rfc.iref.a.3"><b>1.1</b></a></li><li>ACE&nbsp;&nbsp;<a href="#rfc.iref.a.6"><b>1.1</b></a></li><li>ACL&nbsp;&nbsp;<a href="#rfc.iref.a.4"><b>1.1</b></a></li><li>ACL method&nbsp;&nbsp;<a href="#rfc.section.8.1"><b>8.1</b></a></li><li>aggregate privilege&nbsp;&nbsp;<a href="#rfc.iref.a.1"><b>1.1</b></a></li></ul></li><li><a id="rfc.index.C" href="#rfc.index.C"><b>C</b></a><ul><li>Condition Names&nbsp;&nbsp;<ul><li>DAV:allowed-principal (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.12"><b>8.1.1</b></a></li><li>DAV:deny-before-grant (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.5"><b>8.1.1</b></a></li><li>DAV:grant-only (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.6"><b>8.1.1</b></a></li><li>DAV:limited-number-of-aces (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.4"><b>8.1.1</b></a></li><li>DAV:missing-required-principal (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.10"><b>8.1.1</b></a></li><li>DAV:need-privileges (pre)&nbsp;&nbsp;<a href="#rfc.section.7.1.1"><b>7.1.1</b></a></li><li>DAV:no-abstract (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.8"><b>8.1.1</b></a></li><li>DAV:no-ace-conflict (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.1"><b>8.1.1</b></a></li><li>DAV:no-inherited-ace-conflict (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.3"><b>8.1.1</b></a></li><li>DAV:no-invert (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.7"><b>8.1.1</b></a></li><li>DAV:no-protected-ace-conflict (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.2"><b>8.1.1</b></a></li><li>DAV:not-supported-privilege (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.9"><b>8.1.1</b></a></li><li>DAV:number-of-matches-within-limits (post)&nbsp;&nbsp;<a href="#rfc.iref.c.13"><b>9.2</b></a>, <a href="#rfc.iref.c.14"><b>9.4</b></a></li><li>DAV:recognized-principal (pre)&nbsp;&nbsp;<a href="#rfc.iref.c.11"><b>8.1.1</b></a></li></ul></li></ul></li><li><a id="rfc.index.D" href="#rfc.index.D"><b>D</b></a><ul><li>DAV header&nbsp;&nbsp;<ul><li>compliance class 'access-control'&nbsp;&nbsp;<a href="#rfc.section.7.2"><b>7.2</b></a></li></ul></li><li>DAV:acl property&nbsp;&nbsp;<a href="#rfc.section.5.5"><b>5.5</b></a></li><li>DAV:acl-principal-prop-set report&nbsp;&nbsp;<a href="#rfc.section.9.2"><b>9.2</b></a></li><li>DAV:acl-restrictions property&nbsp;&nbsp;<a href="#rfc.section.5.6"><b>5.6</b></a></li><li>DAV:all privilege&nbsp;&nbsp;<a href="#rfc.section.3.11"><b>3.11</b></a></li><li>DAV:allowed-principal precondition&nbsp;&nbsp;<a href="#rfc.iref.d.13"><b>8.1.1</b></a></li><li>DAV:alternate-URI-set property&nbsp;&nbsp;<a href="#rfc.section.4.1"><b>4.1</b></a></li><li>DAV:bind privilege&nbsp;&nbsp;<a href="#rfc.section.3.9"><b>3.9</b></a></li><li>DAV:current-user-privilege-set property&nbsp;&nbsp;<a href="#rfc.section.5.4"><b>5.4</b></a></li><li>DAV:deny-before-grant precondition&nbsp;&nbsp;<a href="#rfc.iref.d.6"><b>8.1.1</b></a></li><li>DAV:grant-only precondition&nbsp;&nbsp;<a href="#rfc.iref.d.7"><b>8.1.1</b></a></li><li>DAV:group property&nbsp;&nbsp;<a href="#rfc.section.5.2"><b>5.2</b></a></li><li>DAV:group-member-set property&nbsp;&nbsp;<a href="#rfc.section.4.3"><b>4.3</b></a></li><li>DAV:group-membership property&nbsp;&nbsp;<a href="#rfc.section.4.4"><b>4.4</b></a></li><li>DAV:inherited-acl-set property&nbsp;&nbsp;<a href="#rfc.section.5.7"><b>5.7</b></a></li><li>DAV:limited-number-of-aces precondition&nbsp;&nbsp;<a href="#rfc.iref.d.5"><b>8.1.1</b></a></li><li>DAV:missing-required-principal precondition&nbsp;&nbsp;<a href="#rfc.iref.d.11"><b>8.1.1</b></a></li><li>DAV:need-privileges precondition&nbsp;&nbsp;<a href="#rfc.section.7.1.1"><b>7.1.1</b></a></li><li>DAV:no-abstract precondition&nbsp;&nbsp;<a href="#rfc.iref.d.9"><b>8.1.1</b></a></li><li>DAV:no-ace-conflict precondition&nbsp;&nbsp;<a href="#rfc.iref.d.2"><b>8.1.1</b></a></li><li>DAV:no-inherited-ace-conflict precondition&nbsp;&nbsp;<a href="#rfc.iref.d.4"><b>8.1.1</b></a></li><li>DAV:no-invert precondition&nbsp;&nbsp;<a href="#rfc.iref.d.8"><b>8.1.1</b></a></li><li>DAV:no-protected-ace-conflict precondition&nbsp;&nbsp;<a href="#rfc.iref.d.3"><b>8.1.1</b></a></li><li>DAV:not-supported-privilege precondition&nbsp;&nbsp;<a href="#rfc.iref.d.10"><b>8.1.1</b></a></li><li>DAV:number-of-matches-within-limits postcondition&nbsp;&nbsp;<a href="#rfc.iref.d.14"><b>9.2</b></a>, <a href="#rfc.iref.d.15"><b>9.4</b></a></li><li>DAV:owner property&nbsp;&nbsp;<a href="#rfc.section.5.1"><b>5.1</b></a></li><li>DAV:principal resource type&nbsp;&nbsp;<a href="#rfc.iref.d.1"><b>4</b></a></li><li>DAV:principal-collection-set property&nbsp;&nbsp;<a href="#rfc.section.5.8"><b>5.8</b></a></li><li>DAV:principal-match report&nbsp;&nbsp;<a href="#rfc.section.9.3"><b>9.3</b></a></li><li>DAV:principal-property-search&nbsp;&nbsp;<a href="#rfc.section.9.4"><b>9.4</b></a></li><li>DAV:principal-search-property-set&nbsp;&nbsp;<a href="#rfc.section.9.5"><b>9.5</b></a></li><li>DAV:principal-URL property&nbsp;&nbsp;<a href="#rfc.section.4.2"><b>4.2</b></a></li><li>DAV:read privilege&nbsp;&nbsp;<a href="#rfc.section.3.1"><b>3.1</b></a></li><li>DAV:read-acl privilege&nbsp;&nbsp;<a href="#rfc.section.3.6"><b>3.6</b></a></li><li>DAV:read-current-user-privilege-set privilege&nbsp;&nbsp;<a href="#rfc.section.3.7"><b>3.7</b></a></li><li>DAV:recognized-principal precondition&nbsp;&nbsp;<a href="#rfc.iref.d.12"><b>8.1.1</b></a></li><li>DAV:supported-privilege-set property&nbsp;&nbsp;<a href="#rfc.section.5.3"><b>5.3</b></a></li><li>DAV:unbind privilege&nbsp;&nbsp;<a href="#rfc.section.3.10"><b>3.10</b></a></li><li>DAV:unlock privilege&nbsp;&nbsp;<a href="#rfc.section.3.5"><b>3.5</b></a></li><li>DAV:write privilege&nbsp;&nbsp;<a href="#rfc.section.3.2"><b>3.2</b></a></li><li>DAV:write-acl privilege&nbsp;&nbsp;<a href="#rfc.section.3.8"><b>3.8</b></a></li><li>DAV:write-content privilege&nbsp;&nbsp;<a href="#rfc.section.3.4"><b>3.4</b></a></li><li>DAV:write-properties privilege&nbsp;&nbsp;<a href="#rfc.section.3.3"><b>3.3</b></a></li></ul></li><li><a id="rfc.index.G" href="#rfc.index.G"><b>G</b></a><ul><li>group&nbsp;&nbsp;<a href="#rfc.iref.g.1"><b>1.1</b></a></li></ul></li><li><a id="rfc.index.I" href="#rfc.index.I"><b>I</b></a><ul><li>inherited ACE&nbsp;&nbsp;<a href="#rfc.iref.i.1"><b>1.1</b></a></li></ul></li><li><a id="rfc.index.M" href="#rfc.index.M"><b>M</b></a><ul><li>Methods&nbsp;&nbsp;<ul><li>ACL&nbsp;&nbsp;<a href="#rfc.section.8.1"><b>8.1</b></a></li></ul></li></ul></li><li><a id="rfc.index.P" href="#rfc.index.P"><b>P</b></a><ul><li>principal&nbsp;&nbsp;<a href="#rfc.iref.p.1"><b>1.1</b></a></li><li>privilege&nbsp;&nbsp;<a href="#rfc.iref.p.2"><b>1.1</b></a></li><li>Privileges&nbsp;&nbsp;<ul><li>DAV:all&nbsp;&nbsp;<a href="#rfc.section.3.11"><b>3.11</b></a></li><li>DAV:bind&nbsp;&nbsp;<a href="#rfc.section.3.9"><b>3.9</b></a></li><li>DAV:read&nbsp;&nbsp;<a href="#rfc.section.3.1"><b>3.1</b></a></li><li>DAV:read-acl&nbsp;&nbsp;<a href="#rfc.section.3.6"><b>3.6</b></a></li><li>DAV:read-current-user-privilege-set&nbsp;&nbsp;<a href="#rfc.section.3.7"><b>3.7</b></a></li><li>DAV:unbind&nbsp;&nbsp;<a href="#rfc.section.3.10"><b>3.10</b></a></li><li>DAV:unlock&nbsp;&nbsp;<a href="#rfc.section.3.5"><b>3.5</b></a></li><li>DAV:write&nbsp;&nbsp;<a href="#rfc.section.3.2"><b>3.2</b></a></li><li>DAV:write-acl&nbsp;&nbsp;<a href="#rfc.section.3.8"><b>3.8</b></a></li><li>DAV:write-content&nbsp;&nbsp;<a href="#rfc.section.3.4"><b>3.4</b></a></li><li>DAV:write-properties&nbsp;&nbsp;<a href="#rfc.section.3.3"><b>3.3</b></a></li></ul></li><li>Properties&nbsp;&nbsp;<ul><li>DAV:acl&nbsp;&nbsp;<a href="#rfc.section.5.5"><b>5.5</b></a></li><li>DAV:acl-restrictions&nbsp;&nbsp;<a href="#rfc.section.5.6"><b>5.6</b></a></li><li>DAV:alternate-URI-set&nbsp;&nbsp;<a href="#rfc.section.4.1"><b>4.1</b></a></li><li>DAV:current-user-privilege-set&nbsp;&nbsp;<a href="#rfc.section.5.4"><b>5.4</b></a></li><li>DAV:group&nbsp;&nbsp;<a href="#rfc.section.5.2"><b>5.2</b></a></li><li>DAV:group-member-set&nbsp;&nbsp;<a href="#rfc.section.4.3"><b>4.3</b></a></li><li>DAV:group-membership&nbsp;&nbsp;<a href="#rfc.section.4.4"><b>4.4</b></a></li><li>DAV:inherited-acl-set&nbsp;&nbsp;<a href="#rfc.section.5.7"><b>5.7</b></a></li><li>DAV:owner&nbsp;&nbsp;<a href="#rfc.section.5.1"><b>5.1</b></a></li><li>DAV:principal-collection-set&nbsp;&nbsp;<a href="#rfc.section.5.8"><b>5.8</b></a></li><li>DAV:principal-URL&nbsp;&nbsp;<a href="#rfc.section.4.2"><b>4.2</b></a></li><li>DAV:supported-privilege-set&nbsp;&nbsp;<a href="#rfc.section.5.3"><b>5.3</b></a></li></ul></li><li>protected property&nbsp;&nbsp;<a href="#rfc.iref.p.3"><b>1.1</b></a></li></ul></li><li><a id="rfc.index.R" href="#rfc.index.R"><b>R</b></a><ul><li><em>REC-XML</em>&nbsp;&nbsp;<a href="#rfc.xref.REC-XML.1">1.2</a>, <a href="#rfc.xref.REC-XML.2">11</a>, <a href="#rfc.xref.REC-XML.3">11</a>, <a href="#REC-XML"><b>16.1</b></a></li><li><em>REC-XML-INFOSET</em>&nbsp;&nbsp;<a href="#rfc.xref.REC-XML-INFOSET.1">9.4.1</a>, <a href="#REC-XML-INFOSET"><b>16.1</b></a></li><li><em>REC-XML-NAMES</em>&nbsp;&nbsp;<a href="#rfc.xref.REC-XML-NAMES.1">10</a>, <a href="#REC-XML-NAMES"><b>16.1</b></a></li><li>Reports&nbsp;&nbsp;<ul><li>DAV:acl-principal-prop-set&nbsp;&nbsp;<a href="#rfc.section.9.2"><b>9.2</b></a></li><li>DAV:principal-match&nbsp;&nbsp;<a href="#rfc.section.9.3"><b>9.3</b></a></li><li>DAV:principal-property-search&nbsp;&nbsp;<a href="#rfc.section.9.4"><b>9.4</b></a></li><li>DAV:principal-search-property-set&nbsp;&nbsp;<a href="#rfc.section.9.5"><b>9.5</b></a></li></ul></li><li>Resource Types&nbsp;&nbsp;<ul><li>DAV:principal&nbsp;&nbsp;<a href="#rfc.iref.r.1"><b>4</b></a></li></ul></li><li><em>RFC2119</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2119.1">1.2</a>, <a href="#RFC2119"><b>16.1</b></a></li><li><em>RFC2251</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2251.1">4.1</a>, <a href="#RFC2251"><b>16.2</b></a></li><li><em>RFC2255</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2255.1">4.1</a>, <a href="#RFC2255"><b>16.2</b></a></li><li><em>RFC2518</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.1">1.1</a>, <a href="#rfc.xref.RFC2518.2">3</a>, <a href="#rfc.xref.RFC2518.3">3.2</a>, <a href="#rfc.xref.RFC2518.4">4</a>, <a href="#rfc.xref.RFC2518.5">4</a>, <a href="#rfc.xref.RFC2518.6">4</a>, <a href="#rfc.xref.RFC2518.7">5</a>, <a href="#rfc.xref.RFC2518.8">5</a>, <a href="#rfc.xref.RFC2518.9">5.1.2</a>, <a href="#rfc.xref.RFC2518.10">5.1.2</a>, <a href="#rfc.xref.RFC2518.11">5.8</a>, <a href="#rfc.xref.RFC2518.12">10</a>, <a href="#rfc.xref.RFC2518.13">11</a>, <a href="#rfc.xref.RFC2518.14">12</a>, <a href="#rfc.xref.RFC2518.15">14</a>, <a href="#rfc.xref.RFC2518.16">14</a>, <a href="#RFC2518"><b>16.1</b></a>, <a href="#rfc.xref.RFC2518.17">A</a><ul><li><em>Section 3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.2">3</a>, <a href="#rfc.xref.RFC2518.8">5</a></li><li><em>Section 5.3</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.3">3.2</a></li><li><em>Section 8.2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.9">5.1.2</a></li><li><em>Section 11</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.10">5.1.2</a></li><li><em>Section 12.14.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.6">4</a>, <a href="#rfc.xref.RFC2518.7">5</a></li><li><em>Section 13.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.4">4</a>, <a href="#rfc.xref.RFC2518.11">5.8</a></li><li><em>Section 13.9</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.5">4</a></li><li><em>Section 23.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.17">A</a></li><li><em>Section 23.3.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2518.12">10</a></li></ul></li><li><em>RFC2616</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.1">1.1</a>, <a href="#rfc.xref.RFC2616.2">1.2</a>, <a href="#rfc.xref.RFC2616.3">1.2</a>, <a href="#rfc.xref.RFC2616.4">12</a>, <a href="#RFC2616"><b>16.1</b></a><ul><li><em>Section 2.1</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.2">1.2</a></li><li><em>Section 2.2</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2616.3">1.2</a></li></ul></li><li><em>RFC2617</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC2617.1">1</a>, <a href="#rfc.xref.RFC2617.2">13</a>, <a href="#RFC2617"><b>16.1</b></a></li><li><em>RFC3023</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3023.1">11</a>, <a href="#rfc.xref.RFC3023.2">12</a>, <a href="#RFC3023"><b>16.1</b></a></li><li><em>RFC3253</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3253.1">5.1.2</a>, <a href="#rfc.xref.RFC3253.2">5.1.2</a>, <a href="#rfc.xref.RFC3253.3">5.1.2</a>, <a href="#rfc.xref.RFC3253.4">7.1.1</a>, <a href="#rfc.xref.RFC3253.5">9.1</a>, <a href="#rfc.xref.RFC3253.6">9.1</a>, <a href="#rfc.xref.RFC3253.7">9.2</a>, <a href="#rfc.xref.RFC3253.8">9.3</a>, <a href="#rfc.xref.RFC3253.9">9.4</a>, <a href="#rfc.xref.RFC3253.10">9.5</a>, <a href="#RFC3253"><b>16.1</b></a><ul><li><em>Section 1.6</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3253.1">5.1.2</a>, <a href="#rfc.xref.RFC3253.4">7.1.1</a></li><li><em>Section 3.6</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3253.5">9.1</a>, <a href="#rfc.xref.RFC3253.7">9.2</a>, <a href="#rfc.xref.RFC3253.8">9.3</a>, <a href="#rfc.xref.RFC3253.9">9.4</a>, <a href="#rfc.xref.RFC3253.10">9.5</a></li><li><em>Section 3.8</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3253.6">9.1</a></li><li><em>Section 3.12</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3253.2">5.1.2</a></li></ul></li><li><em>RFC3530</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3530.1">6</a>, <a href="#RFC3530"><b>16.1</b></a></li><li><em>RFC3629</em>&nbsp;&nbsp;<a href="#rfc.xref.RFC3629.1">11</a>, <a href="#RFC3629"><b>16.1</b></a></li></ul></li><li><a id="rfc.index.U" href="#rfc.index.U"><b>U</b></a><ul><li><em>UNICODE4</em>&nbsp;&nbsp;<a href="#rfc.xref.UNICODE4.1">9.4</a>, <a href="#UNICODE4"><b>16.2</b></a></li></ul></li></ul></div></section><section id="rfc.authors" class="avoidbreakinside"><h2><a href="#rfc.authors">Authors' Addresses</a></h2><address><b>Geoffrey Clemm</b><br>IBM<br>20 Maguire Road<br>Lexington, MA&nbsp;02421<br>EMail: <a href="mailto:geoffrey.clemm@us.ibm.com">geoffrey.clemm@us.ibm.com</a></address><address><b>Julian F. Reschke</b><br>greenbytes GmbH<br>Salzmannstrasse 152<br>Muenster, NW&nbsp;48159<br>Germany<br>EMail: <a href="mailto:julian.reschke@greenbytes.de">julian.reschke@greenbytes.de</a></address><address><b>Eric Sedlar</b><br>Oracle Corporation<br>500 Oracle Parkway<br>Redwood Shores, CA&nbsp;94065<br>EMail: <a href="mailto:eric.sedlar@oracle.com">eric.sedlar@oracle.com</a></address><address><b>Jim Whitehead</b><br>U.C. Santa Cruz, Dept. of Computer Science<br>1156 High Street<br>Santa Cruz, CA&nbsp;95064<br>EMail: <a href="mailto:ejw@cse.ucsc.edu">ejw@cse.ucsc.edu</a></address></section><section id="rfc.copyright"><h2><a href="#rfc.copyright">Full Copyright Statement</a></h2><p>Copyright &copy; The Internet Society (2004).</p><p>This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.</p><p>This document and the information contained herein are provided on an &#8220;AS IS&#8221; basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.</p></section><section id="rfc.ipr"><h2><a href="#rfc.ipr">Intellectual Property</a></h2><p>The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.</p><p>Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at <a href="http://www.ietf.org/ipr">http://www.ietf.org/ipr</a>.</p><p>The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at <a href="mailto:ietf-ipr@ietf.org">ietf-ipr@ietf.org</a>.</p></section><section id="n-acknowledgment"><h2><a href="#n-acknowledgment">Acknowledgment</a></h2><p>Funding for the RFC Editor function is currently provided by the Internet Society.</p></section></body></html>
